Instruction: how to tell if a cat is checking if you are breathing in your sleep.

1. Recognizing Feline Behavior During Sleep

1.1 Common Cat Habits

Cats display several routine behaviors that can be mistaken for random activity when they are near a sleeping person. Understanding these patterns helps determine whether a feline is actually monitoring the owner’s respiration.

Quiet hovering - A cat often positions itself on the edge of the bed, eyes fixed on the chest. This stance allows the animal to feel subtle rises and falls of the ribcage, indicating an awareness of the breathing cycle.
Gentle paw tapping - Light, rhythmic taps with a front paw correspond to the owner’s inhalation rhythm. The cat adjusts the frequency of taps to match the breath rate, suggesting a deliberate synchrony.
Soft purring near the face - When a cat purrs while its nose is close to the sleeper’s mouth, it can pick up airflow changes. The purr may increase in intensity as the breath deepens, reflecting real‑time monitoring.
Kneading the blanket - Repetitive pressing of paws against fabric creates a tactile feedback loop. The pressure changes as the body expands and contracts during breathing, giving the cat a physical cue.
Sniffing pauses - Cats often inhale sharply, pause, then exhale slowly. A series of short sniffs timed with the owner’s breaths indicates the animal is sampling the air for temperature and humidity fluctuations associated with inhalation.

These habits are not random; they provide the cat with continuous, low‑level data about the sleeper’s breathing. Recognizing each behavior as part of a coordinated observation can help owners interpret whether their pet is simply comfortable or actively checking the respiration of a sleeping companion.

1.2 Unusual Sleep-Related Activities

When a cat monitors a sleeping person, the behavior diverges from ordinary nighttime companionship. The animal positions itself near the head, often aligning its body with the breath flow. Its whiskers may point toward the nostrils, and the cat’s own respiration tends to synchronize with the human’s, creating a subtle rhythm match. Occasionally the cat will gently tap the face with a paw or nudge the cheek, testing for movement. These actions constitute the core indicators of a feline check on the sleeper’s breathing.

Key observable cues include:

Proximity: the cat rests directly on the pillow or beside the chin.
Whisker orientation: whiskers angled toward the nose, suggesting sensory focus.
Respiratory mirroring: cat’s breaths rise and fall in concert with the human’s.
Light paw contact: brief, soft taps on the face or mouth area.
Head tilt: the cat angles its head to better detect airflow.

Distinguishing this from routine grooming or warmth-seeking requires attention to timing. The cat initiates the behavior shortly after the person falls asleep and maintains it for several minutes, then disengages once the breathing pattern stabilizes. If the cat resumes the activity after a brief interruption, it likely continues to verify the respiratory rhythm.

Understanding these patterns enables owners to recognize when a cat is actively assessing a sleeper’s breath, rather than simply sharing the bed for comfort.

2. Identifying "Breathing Check" Behaviors

2.1 Close Proximity and Observation

When a cat monitors a sleeping person’s respiration, the most reliable indicator is its sustained presence within arm’s length of the bed. The animal positions itself so that any subtle chest rise is within its peripheral vision and tactile range. Observe the following behaviors that confirm close‑proximity surveillance:

The cat settles on the pillow, the mattress edge, or the bedside rail, aligning its body parallel to the sleeper’s torso.
Ears swivel independently, tracking the faint rhythm of inhalation and exhalation; each ear may tilt forward during inhalation and relax during exhalation.
Whiskers point forward and slightly flare, increasing sensitivity to airflow changes caused by the sleeper’s breath.
The eyes remain half‑closed, pupils dilated, allowing the cat to maintain a soft focus on the chest while avoiding full alertness.
A paw may rest lightly on the sleeper’s abdomen or chest, providing direct tactile feedback on the rise and fall of the ribcage.
Tail movements become slow and rhythmic, mirroring the breathing pattern; a gentle swish often coincides with each inhalation.

These cues, taken together, demonstrate that the cat is deliberately maintaining a close distance to evaluate the breathing cycle while the owner is asleep.

2.2 Tactile Exploration

Cats rely on tactile cues to assess a sleeping human’s respiration. Their whiskers detect minute air currents generated by each inhalation, while the pads of their paws sense the rise and fall of the chest. When a cat is monitoring breathing, it typically adopts a low‑profile posture, allowing maximal contact with the body. The animal may place a forepaw gently on the ribcage, adjust its weight to follow the subtle expansion, or press its cheek against the neck to capture temperature changes associated with exhaled air.

Key tactile indicators of this behavior include:

Light, intermittent paw pressure synchronized with the breath cycle.
Whisker orientation directed toward the face or chest, shifting with each inhalation.
Consistent head or cheek placement against the skin, maintaining contact for several breaths.
Minimal movement aside from adjustments that track the breathing rhythm.

Distinguishing these signals from grooming or play involves observing the duration and regularity of the contact. A cat that maintains steady, low‑force pressure for an extended period, aligns its sensory organs with the breathing source, and refrains from sudden pouncing or licking is likely engaged in respiratory monitoring rather than routine interaction.

2.2.1 Pawing

Cats often use their paws to probe a sleeping human’s chest or abdomen. When a cat places a gentle, rhythmic paw on the body, it is typically testing the rise and fall of the ribcage. The movement is usually light, not aggressive, and the cat may pause intermittently to assess the pattern of motion.

Key characteristics of paw‑based monitoring:

Contact pressure - the cat applies just enough force to feel the surface without causing discomfort.
Timing - paw placement aligns with the breathing cycle; the cat may lift the paw briefly during exhalation and replace it during inhalation.
Repetition - a sequence of several taps over a minute suggests the cat is gathering data rather than seeking play.
Body positioning - the cat often positions itself directly over the chest or stomach, indicating a focus on respiratory movement.

If the pawing stops once the cat detects a steady rhythm, the feline has likely confirmed the breathing pattern. Conversely, erratic or prolonged pawing may indicate uncertainty or a response to irregular breathing. Observing these nuances allows owners to discern whether their cat is actively checking for breath during sleep.

2.2.2 Nudging

When a cat rests near a sleeping person, it may employ a subtle behavior known as nudging to assess the host’s respiratory rhythm. This action involves brief, low‑force contact-typically a paw tap, head press, or tail brush-delivered at intervals that correspond to the breath cycle. The cat’s sensory apparatus, especially whisker and vibrissae receptors, detects minute air movements, allowing it to gauge inhalation and exhalation without waking the human.

Key characteristics of nudging in this context include:

Contact duration of 0.2-0.5 seconds, followed by a pause that matches the average adult breathing interval (≈4-6 seconds).
Repetitive pattern synchronized with the sleeper’s inhale‑exhale sequence.
Minimal audible disturbance; the cat’s paws land softly on blankets or skin.
Body posture that maintains visual access to the chest or abdomen, often with one eye half‑closed.

To verify whether a cat is using nudging to monitor breathing, follow a systematic observation protocol:

Position a night‑vision camera or infrared recorder at the foot of the bed.
Record a minimum of two sleep cycles (≈10 minutes).
Identify moments of contact between cat and sleeper; note timestamps.
Extract the sleeper’s respiration trace using a contactless sensor (e.g., a mattress‑embedded radar).
Correlate contact timestamps with peaks in the respiration waveform; a consistent alignment indicates nudging.

Interpretation guidelines:

Alignment in >70 % of contacts suggests deliberate monitoring rather than random movement.
Random or sporadic contacts with no temporal correlation imply typical feline repositioning.
Consistent head‑presses directly over the chest, coupled with synchronized timing, represent the most definitive nudging pattern.

Understanding nudging helps differentiate benign sleep companionship from potential stress‑induced behaviors. Recognizing the pattern allows owners to respond appropriately-providing a comfortable perch or adjusting the sleeping environment-to maintain both human rest quality and feline well‑being.

2.2.3 Licking

As a feline behavior specialist, I observe that licking can serve as a direct cue that a cat is monitoring a sleeping owner's breathing. When a cat gently laps a hand, foot, or the side of the face, it often seeks tactile feedback about subtle chest movements. The rhythmic pressure of the tongue against skin transmits vibrations caused by inhalation and exhalation, allowing the cat to assess the continuity of airflow.

Key characteristics of this licking behavior include:

Soft, intermittent strokes rather than continuous grooming; the cat pauses to detect changes in motion.
Placement near the thoracic area (e.g., neck, clavicle) where the rise and fall of the ribcage are most perceptible.
A brief cessation if the cat perceives a pause in breathing, followed by a resumption once regular rhythm returns.
Accompanying low‑frequency purring, which may amplify the cat’s sensitivity to the host’s respiratory sounds.

These patterns differentiate respiratory‑monitoring licking from typical grooming. Regular grooming lacks the focused, intermittent contact and the correlation with the owner's breathing cycle. Recognizing the described licking cues enables accurate assessment of whether a cat is actively checking for breath during sleep.

2.3 Auditory Cues

Cats use subtle sounds to monitor a sleeping human’s respiration. An experienced observer can identify three primary auditory indicators that a feline is actively listening for breath patterns.

First, a low‑frequency purr that intensifies when the person’s breathing slows suggests the cat is synchronizing its own vibration with the host’s inhale‑exhale cycle. The purr may shift from a steady 25 Hz tone to a softer, intermittent rhythm, reflecting the cat’s attempt to match the slower airflow.

Second, intermittent, soft chirps or “chatters” often occur when the cat detects irregularities in the breath. A brief, high‑pitched chirp followed by a pause aligns with a momentary gasp or snore, signaling the cat’s heightened auditory attention.

Third, a faint, rhythmic foot‑pad padding can be heard as the cat circles the bed. The cadence of these steps mirrors the breathing rate: slower steps correspond to deeper, slower breaths, while quicker steps appear when the sleeper’s respiration becomes shallow or fragmented.

Practical application:

Listen for a purr that changes tempo in response to breathing depth.
Note any short, sharp chirps that coincide with irregular breaths.
Observe the pattern of foot‑pad sounds; a matching rhythm indicates the cat is tracking respiration.

By focusing on these auditory cues, owners can determine whether their cat is actively checking the sleeper’s breathing pattern.

3. Understanding the Cat's Motivation

3.1 Instinctual Caregiving

Cats possess a built‑in caregiving instinct that activates when they sense vulnerability in a companion. During a human’s sleep, this instinct can drive the animal to monitor subtle physiological cues, including the rhythm of breathing. The behavior is not random; it reflects a deep‑seated drive to protect and maintain proximity to a dependent individual.

When a cat is actively checking a sleeper’s breath, the following observable actions typically occur:

Gentle paw placement on the chest or abdomen, often accompanied by a light, rhythmic pressure that matches the inhalation cycle.
Soft, repetitive head nudges directed toward the nose or mouth area, timed to coincide with inhalations.
Quiet, sustained purring that intensifies as the breathing pattern stabilizes, indicating a calming feedback loop.
Slow, deliberate blinking or half‑closed eyes while the cat remains in close contact, reflecting a state of focused vigilance.

These responses stem from the feline’s ancestral role as a caregiver for kittens, where monitoring temperature, heartbeat, and respiration ensured offspring survival. The same neural pathways are repurposed when the cat perceives a human as a dependent, prompting the animal to verify that respiration continues uninterrupted.

Interpretation of these signals requires attention to context. A cat that remains stationary, maintains light physical contact, and synchronizes its movements with the sleeper’s breath is likely performing instinctual caregiving. In contrast, fleeting touches, sudden movements, or aggressive swatting suggest curiosity or play rather than monitoring.

Understanding this instinctual framework helps owners differentiate between benign caregiving behavior and other nocturnal activities. Recognizing the specific patterns outlined above provides a reliable method for assessing whether a cat is truly checking a person’s breathing while they sleep.

3.2 Bond Reinforcement

Observing a cat that monitors your respiration while you sleep offers a practical illustration of bond reinforcement. When a feline consistently returns to the bedside, aligns its body with the sleeper, and adjusts its posture in response to subtle changes in breath, the animal is strengthening the social connection through reciprocal attention.

Key indicators of this reinforcement include:

Proximity maintenance - the cat stays within arm’s reach, positioning itself so that any shift in chest movement is easily perceived.
Responsive pacing - periods of stillness alternate with gentle paw taps or head nudges timed to the sleeper’s inhalation and exhalation cycles.
Vocal feedback - soft trills or low purrs coincide with the onset of a breath, signaling acknowledgment of the shared rhythmic activity.
Physical adjustment - the cat re‑aligns its spine or rotates its tail as the sleeper’s breathing depth changes, demonstrating real‑time monitoring.

These behaviors serve two functions. First, they provide the cat with confirmation that the human remains alive and responsive, satisfying its instinctual need for safety cues. Second, the repeated interaction reinforces the mutual bond, encouraging the cat to continue offering protective vigilance during sleep.

From an expert perspective, the presence of these patterns confirms that the animal is actively engaging in bond reinforcement through respiratory monitoring. Absence of such cues suggests either a lack of interest or insufficient attachment, prompting a reassessment of the cat’s social engagement strategies.

3.3 Attention Seeking

Cats often display attention‑seeking behavior when they are monitoring a sleeping human’s respiration. This behavior manifests in specific, observable actions that differentiate it from ordinary nighttime activity.

When a cat is focused on your breathing, you may notice the following signs:

Persistent positioning near the head or chest, often perched on the pillow or draped across the torso.
Repeated gentle pawing or nudging of the face, especially when the breath becomes irregular.
Soft, rhythmic vocalizations timed with inhalations, such as low trills or quiet mews.
Sudden stillness combined with intense stare, eyes fixed on the nostrils or mouth area.
Light tapping of the body with the tail, creating a subtle tapping motion that coincides with each breath.

These actions serve the cat’s need for interaction and reassurance. The animal seeks confirmation that the human remains alive and responsive, a trait rooted in its instinctual caregiving role. Recognizing the pattern-continuous proximity, synchronized movements, and focused attention-allows you to determine whether the cat is merely restless or actively checking your breathing during sleep.

4. Differentiating From Other Behaviors

4.1 Seeking Warmth

As a feline behavior specialist, I explain how a cat’s pursuit of warmth can serve as an indicator that it is monitoring your breathing while you sleep. Cats are thermally motivated mammals; they gravitate toward heat sources to conserve energy. When a cat settles on your chest, abdomen, or pillow, the behavior often extends beyond simple comfort. The animal uses the rise and fall of your body temperature, which correlates with each breath, to confirm that you remain alive and breathing.

Key observations that link warmth‑seeking to respiration monitoring:

The cat positions itself directly over your breathing zone (chest or neck) rather than a peripheral spot.
It remains motionless for extended periods, only adjusting when your breathing pattern changes (e.g., deeper breaths during REM sleep).
The animal’s paws or body make intermittent, gentle pressure that aligns with each inhalation, suggesting a tactile response to airflow.
When you shift position or cease breathing temporarily (e.g., during a brief apnea), the cat may nudge or reposition, indicating detection of altered warmth or airflow.

Understanding this pattern helps owners differentiate between ordinary heat‑seeking and purposeful respiratory surveillance. If the cat consistently exhibits the behaviors listed above, it is likely using warmth as a proxy to ensure your breathing continues throughout the night.

4.2 Playfulness

Understanding a cat’s playful monitoring while you are asleep requires recognizing specific behaviors that differ from predatory or protective actions. Playfulness manifests as light‑hearted engagement, often accompanied by rapid movements, vocalizations, and an exaggerated posture that signals enjoyment rather than vigilance.

Typical playful cues include:

Sudden pouncing on the pillow or blanket, followed by a quick retreat.
Gentle paw taps on the chest or face, timed with the rise and fall of breath.
Soft chirps or trills emitted as the cat follows the rhythm of your respiration.
Rolling onto the back with limbs splayed, then batting at the air above your head.

These actions usually occur in short bursts, repeat several times, and end with the cat grooming itself or seeking attention. The cat’s tail may flick side‑to‑side, and the ears remain forward, indicating curiosity rather than tension.

When playfulness dominates the interaction, the cat is less likely to intervene if breathing slows or pauses. Instead, the animal treats the breathing pattern as a moving target for amusement, adjusting its antics to match the perceived rhythm. Recognizing this distinction helps owners differentiate between a cat that is merely entertained and one that is actively monitoring for health concerns.

4.3 Territorial Marking

Cats rely on scent to map their environment and to assess the status of individuals within their domain. When a cat approaches a sleeping person, it may engage in territorial marking behaviors that double as a physiological check. The most common forms of marking in this context are:

Rubbing the cheeks, chin, or flanks against the sleeper’s face, neck, or chest. The cat deposits facial pheromones while simultaneously sampling the human’s breath through close contact.
Light pawing or kneading on the pillow or blanket. This action releases scent from the paw pads and allows the cat to feel subtle vibrations caused by breathing.
Gentle tail‑tip tapping on the nose or mouth area. The movement triggers the cat’s vibrissae, which detect airflow changes, while the tail tip leaves a trace of scent glands.

These behaviors serve two functions: they reaffirm the cat’s claim over the sleeping space and provide continuous feedback on the occupant’s respiratory rhythm. A cat that pauses its marking after a few seconds may have registered a steady breath pattern; a cat that repeats the action or intensifies rubbing often indicates an irregular or shallow breathing pattern that has captured its attention.

Observing the frequency and intensity of these marking actions offers a practical method for determining whether a cat is monitoring your breath during sleep. Consistent, brief contacts suggest normal respiration; prolonged, repeated contacts may signal the cat’s attempt to gather more information about an atypical breathing pattern.

5. Interpreting Cat Communication

5.1 Body Language

When a cat observes a sleeping human, its posture, facial expression, and subtle movements reveal whether it is tracking respiration. The following body‑language indicators are reliable markers.

Erect ears, forward‑pointed - The cat keeps its ear tips aligned toward the head, indicating heightened auditory focus on the gentle rise and fall of breath.
Steady, low‑frequency tail flick - A slow, rhythmic tail movement mirrors the breathing cycle; the cat may synchronize its tail sways with each inhalation and exhalation.
Relaxed neck muscles with occasional head lifts - The neck remains loose, but the cat lifts its head briefly each time the chest expands, confirming detection of airflow.
Whisker orientation toward the nostrils - Whiskers point slightly forward, positioned to capture subtle changes in air currents generated by the sleeper’s breathing.
Paw placement and pressure - One front paw may rest lightly on the chest or abdomen, applying minimal pressure that allows the cat to feel the subtle rise of the torso.
Soft, intermittent blinking - Slow blinks accompany periods of focused observation, reducing visual distraction while maintaining vigilance.

Together, these cues form a coherent pattern: the cat remains poised, with sensory organs directed at the breathing source, while its own movements echo the rhythm of the human’s respiration. Recognizing this suite of behaviors enables precise assessment of whether a feline companion is actively monitoring a sleeper’s breath.

5.2 Vocalizations

Cats use a narrow range of sounds to monitor a sleeping human’s respiration. The most reliable vocal cues appear when the animal is close enough to detect subtle airflow changes.

A soft, continuous chirp indicates the cat is listening for the rhythmic rise and fall of the chest. The chirp often pauses at the end of each inhalation, resuming with the next exhalation.
A brief, high‑pitched trill occurs when the cat detects a pause in breathing, such as a shallow breath or temporary apnea. The trill serves as a prompt for the cat to re‑position for better acoustic access.
A low, rumbling purr that fluctuates in tempo mirrors the owner’s breathing pattern. Faster purr cycles align with rapid breaths; slower cycles correspond to deeper, slower breaths.
A short, sharp meow is emitted when the cat perceives irregular breathing, signaling heightened alertness or curiosity. The meow is typically followed by a pause as the cat reassesses the airflow.

These vocalizations are often accompanied by subtle body language: ears forward, whiskers tilted toward the nostrils, and a crouched posture that maximizes proximity to the airflow source. By observing the type, timing, and repetition of these sounds, an owner can determine whether the cat is actively checking the breathing rhythm during sleep.

6. Responding to Your Cat's Actions

6.1 Acknowledging Their Presence

When a cat settles beside you during the night, the first sign that it is actively monitoring your breathing is the cat’s deliberate acknowledgement of your presence. This behavior is distinct from casual proximity and reveals a purposeful focus.

The cat will often:

Position itself within a few inches of your face, aligning its nose with your nostrils.
Maintain a steady, low‑volume purr that synchronizes with the rhythm of your breaths.
Keep its eyes half‑closed, yet directed toward your airway, occasionally flicking its ears toward each inhalation and exhalation.

These actions demonstrate that the cat is not merely sharing the sleeping space but is attuned to the subtle airflow changes you produce. By recognizing this deliberate positioning, you can confirm that the feline is actively checking your respiration rather than merely occupying a warm spot.

In practice, observe the cat’s body language after you fall asleep. If the animal adjusts its stance each time you breathe-shifting slightly forward on inhalation and retreating on exhalation-this pattern confirms conscious monitoring. The cat’s consistent, purposeful engagement with your breathing cycle is the hallmark of acknowledgment in this context.

6.2 Maintaining a Consistent Routine

As a veterinary behavior specialist, I emphasize that a stable daily schedule directly influences a cat’s nocturnal attentiveness. Cats thrive on predictability; when feeding, play, and rest occur at the same times each day, they develop a clear expectation of owner activity. This expectation extends to nighttime, where the animal may position itself to observe the owner’s breathing patterns if the routine signals that the owner will be asleep.

Consistent routines create reliable cues for the cat’s internal clock. When the owner follows a fixed bedtime, the cat learns to associate the pre‑sleep period with a specific sequence of events-dim lighting, reduced movement, and quiet. Over time, the cat may adopt a monitoring posture, such as sitting at the foot of the bed or curling near the chest, to assess the rhythm of the owner’s breath. Disruptions in the schedule-late meals, irregular play sessions, or variable sleep times-confuse these cues and reduce the likelihood of the cat exhibiting monitoring behavior.

To determine whether a cat is checking your respiration during sleep, maintain the following routine components:

Feed the cat at the same times each morning and evening; avoid late‑night snacks.
Conduct a brief interactive play session 30-45 minutes before bedtime to expend energy.
Dim lights and lower household noise 15 minutes prior to sleep to signal the transition.
Place the cat’s sleeping area or favorite perch adjacent to the bed consistently each night.
Record observations for a week, noting the cat’s position, movements, and any pauses that coincide with your breathing cycles.

By adhering strictly to these schedule elements, you create an environment where the cat’s monitoring behavior becomes observable and measurable. Consistency eliminates extraneous variables, allowing you to assess the cat’s response to your breathing with confidence.

7. When to Be Concerned

7.1 Excessive or Disruptive Behavior

As an authority on feline behavior, I explain how excessive or disruptive actions can reveal that a cat is monitoring a person’s respiration during sleep.

When a cat displays heightened activity while the owner lies still, the following patterns are typical indicators:

Repeated pawing or tapping the chest area, especially after a pause in the cat’s usual grooming routine.
Sudden, loud meowing or chirping that interrupts the sleeper’s quiet period.
Persistent pacing around the bed, with the animal stopping directly above the torso and staring intently at the chest.
Aggressive kneading that intensifies when the sleeper’s breath slows or becomes irregular.
Frequent attempts to nudge the head or shift the blanket, often timed with each inhalation or exhalation.

These behaviors exceed normal nighttime routines and suggest the cat is actively checking for breath cues. Recognizing the shift from routine grooming or gentle companionship to persistent, interruptive actions helps owners assess whether their feline companion is engaged in respiratory monitoring rather than ordinary nocturnal activity.

7.2 Sudden Changes in Habit

Cats are highly attuned to subtle environmental cues. When a feline suddenly alters its usual nighttime routine, the deviation often signals a shift in focus toward the host’s respiration. Recognizing these habit changes enables owners to determine whether the animal is actively monitoring breathing during sleep.

A cat that normally sleeps on a distant perch may abruptly relocate to the foot of the bed, positioning itself within arm’s reach of the sleeper’s chest. This relocation typically occurs without provocation such as temperature change or hunger, indicating a purposeful adjustment. Likewise, a feline that habitually rises at sunrise may begin to rise earlier, positioning itself near the sleeper before the first breath is taken, suggesting a pre‑emptive check.

Observable behaviors that accompany sudden habit changes include:

Persistent pawing or gentle nudging of the sleeper’s face or chest shortly after the person settles into bed.
Increased vocalization-soft chirps or low trills-directed at the sleeper’s head during the first minutes of sleep.
Repeated circling of the mattress edge before finally settling directly on the sleeper’s torso.
Heightened alertness to any irregular breathing pattern, manifested by the cat’s head tilting or ears rotating toward the chest.

These actions are distinct from typical grooming, play, or hunting instincts. The timing aligns with the onset of the host’s sleep cycle, and the cat’s focus remains fixed on the respiratory zone rather than on food or litter box access.

When evaluating whether a cat is checking breathing, consider the baseline routine documented over several nights. Any abrupt shift-such as moving from a distant location to direct contact, altering wake‑up time, or introducing new tactile interactions-constitutes a sudden change in habit. Correlating these shifts with the cat’s proximity to the sleeper’s airway provides a reliable indicator that the animal is actively assessing breath during the night.