Rat Body Language Guide

Bruxing is the rhythmic grinding of the incisors together, producing a soft, repetitive clicking or chattering sound. You will usually hear it when your rat is relaxed , while being stroked, settled in your lap, or dozing in a favourite hammock.

When bruxing intensifies, the jaw movement can cause the eyes to vibrate in and out of the socket. This is called boggling. It looks alarming the first time you see it, but it is entirely normal. The jaw muscles in rats pass behind the eye socket, so vigorous grinding physically pushes the eyes outward with each movement.

What it means: Contentment and relaxation. Bruxing is widely considered the rat equivalent of a cat’s purr. The more intense the bruxing (and the more the eyes boggle), the happier the rat.

Context matters: Occasional bruxing can also occur during mild stress , for example, in a new environment or at the vet. In these cases, it appears to serve a self-soothing function, similar to how humans might hum or fidget when nervous. Look at the overall body language: a relaxed, loose body means happy bruxing. A tense, hunched body with bruxing may indicate the rat is trying to calm itself.

What to do: If your rat is bruxing while you handle them, you are doing something right. Keep doing it. If they are bruxing in a stressful situation, speak softly and give them the option to retreat to a safe space.

Rat ears are surprisingly expressive and one of the quickest ways to read mood.

Ears forward and upright: Alert, curious, interested. This is the default “exploring” position. A rat with forward ears and whiskers fanned out is actively investigating something.

Ears relaxed and slightly to the side: Calm and comfortable. Often seen during gentle handling or while resting in a group. This is the “all is well” position.

Ears flat against the head: This signals submission, fear, or pain. A rat flattening its ears during an encounter with another rat is saying “I am not a threat.” A rat flattening its ears when alone or being handled may be in discomfort or frightened.

One ear forward, one back: The rat is processing two things at once , monitoring something behind while investigating something ahead. Rats have excellent directional hearing and can move each ear independently.

What to do: Use ear position as a quick mood check. If you pick up your rat and the ears flatten immediately, they may not be in the mood for handling. If the ears stay relaxed or perk forward, they are comfortable. Ears are especially useful for reading new rats whose personality you are still learning.

Puffed or piloerect fur: The fur stands up, making the rat look larger and rougher than usual. This is called piloerection and it has several possible causes:

Cold: If the room temperature has dropped or there is a draught near the cage, puffed fur is simply the rat trying to trap warm air. Check the environment first.

Illness or pain: A rat that is puffed up, hunched, and less active than usual may be unwell. This is one of the most important early warning signs of respiratory infection, which is common in pet rats. If puffed fur persists for more than a few hours alongside reduced activity, a vet visit is warranted.

Fear or aggression: During confrontations, rats puff their fur to appear larger. Combined with sidling (see below), this is a dominance or defensive display.

Belly-up posture: A rat lying on its back and exposing its belly , especially while being stroked , is showing deep trust. The belly is the most vulnerable area. Rats that roll onto their back during play or handling have accepted you completely as part of their social group. Never grab, poke, or startle a rat in this position. It takes time to earn and seconds to lose.

Hunched posture: A rat sitting hunched with a rounded back, often with half-closed eyes and puffed fur, is typically unwell. Healthy rats are alert, mobile, and curious. A hunched rat that stays in one spot needs monitoring and likely a vet check.

Rats are intensely playful animals, and their play can look violent to new owners. Understanding the difference between play and genuine aggression is essential.

Wrestling and pinning: Two rats tumbling over each other, pinning one another down, and immediately bouncing back for more is normal play. Young rats especially will wrestle for extended periods. The pinned rat does not squeal, and both rats keep coming back voluntarily.

Chasing: Rats chase each other around the cage and during free-roam time. Playful chasing involves both rats taking turns as chaser and chased. If the same rat is always fleeing and never chasing back, it may be bullying rather than play.

Sidling (crab-walking): A rat approaching another sideways, often with slightly puffed fur and an arched back. This can be either playful posturing (especially in young bucks) or a genuine dominance challenge. In play, the sidling rat is loose and bouncy. In a real confrontation, the rat is stiff, tense, and slow.

Boxing: Two rats standing on their hind legs and pushing at each other with their front paws. This is almost always play or mild dominance sorting. It rarely escalates.

How to tell play from real aggression:

Play is silent or accompanied by ultrasonic “laughter” (above human hearing range). Real fights produce audible squealing, screaming, or hissing. Play involves no blood and no biting that breaks skin. If you see blood, separate the rats immediately. Play is reciprocal , both rats engage willingly. If one rat is always the target and tries to escape, intervene.

What to do: Let them play. Resist the urge to separate wrestling rats unless there is audible distress or visible injury. Interrupting normal play disrupts social bonding and hierarchy development.

Freezing: A rat that suddenly stops moving and stands completely still, often with wide eyes and flattened ears, has detected a perceived threat. This is a hardwired prey-animal response , movement attracts predators, so the rat’s instinct is to become invisible. Common triggers include sudden loud noises, unfamiliar people, shadows passing overhead (mimicking a bird of prey), and strong unfamiliar smells.

What to do: Do not pick the rat up or make sudden movements. Stay calm, speak in a low soft voice, and remove the source of the scare if possible. The rat will unfreeze once it assesses the threat has passed. Repeated freezing in the same context means that trigger is genuinely frightening to your rat and should be managed.

Fleeing and hiding: A rat that bolts for cover is more frightened than one that freezes. Ensure your rat always has access to a hide or enclosed space where it feels safe. Rats that cannot escape to a safe spot when scared become chronically stressed.

Stress bar (red discharge around eyes and nose): A red-brown discharge called porphyrin, produced by the Harderian gland behind the eye. Small amounts are normal, especially after sleep. Excessive or persistent porphyrin staining around both eyes and the nose indicates the rat is stressed, unwell, or not sleeping properly. Common causes include respiratory illness, chronic stress, poor cage placement (too much light, noise, or draught), and pain.

What to do: If you notice heavy porphyrin, assess the rat’s environment and health. Check for sneezing, laboured breathing, lethargy, and weight loss. A vet visit is advisable if porphyrin is accompanied by any other symptom.

Most rat communication happens in the ultrasonic range (above 20 kHz), which humans cannot hear. The sounds we can hear are the loud ones , and they usually mean something important.

Squeaking: A short, sharp squeak during handling or interaction with another rat typically means “that hurt” or “stop that.” It is a protest signal. If your rat squeaks when you pick it up, check your grip , you may be holding too tightly or pressing a sore spot.

Prolonged squealing: Louder and more sustained than a squeak. This is genuine distress or pain. During a fight, squealing means the interaction has crossed from play into real aggression. Separate the rats immediately. During handling, prolonged squealing may indicate injury or illness.

Hissing: A rare sound in pet rats. A hissing rat is either very frightened or very angry. Give it space immediately. Hissing is a final warning before a bite.

Chattering (not bruxing): A rapid, harsh clicking different from the soft rhythm of bruxing. This can indicate respiratory distress , the rat is struggling to breathe through congested airways. If chattering is accompanied by laboured breathing, visible side-heaving, or a head tilt, seek veterinary care urgently.

Ultrasonic calls: Research has identified over 22 distinct ultrasonic call types in rats, including what researchers describe as “laughter” , rapid 50 kHz chirps produced during play and tickling. While you cannot hear these, knowing they exist helps explain why your rats sometimes seem to be playing in complete silence. They are communicating constantly , just above your hearing range.

What to do: Any audible vocalisation from a rat deserves attention. Rats are naturally quiet animals, so sounds you can hear are usually significant. React calmly and assess what triggered the sound.

Rats are scent-driven animals. Their sense of smell is vastly more important to them than vision, and they use scent to communicate ownership, identity, reproductive status, and social rank.

Urine marking: Both male and female rats leave small drops of urine as they walk. This is not a house-training failure , it is deliberate communication. Bucks (males) tend to mark more heavily, especially uncastrated bucks. The urine contains information about the individual rat’s identity, health, and hormonal status.

Rubbing: Rats have scent glands on their flanks and will rub their sides against objects, cage furniture, and you. A rat rubbing its side against your hand is marking you as part of its territory. This is a compliment.

Chin and cheek rubbing: Similar to flank rubbing but using the chin and cheeks, where additional scent glands are located. Rats that chin-rub your fingers or clothing are claiming you.

Marking new environments: When you introduce a rat to a new space, it will immediately begin scent-marking by trailing small urine drops and rubbing against surfaces. This is how rats make an unfamiliar space feel safe. It is completely normal and expected during free-roam time.

What to do: Accept it. Scent marking is a fundamental rat behaviour and cannot be trained out. You can manage it by using washable blankets during free-roam time and cleaning marked surfaces regularly. Fleece cage liners wash easily. If urine marking increases suddenly, it may indicate stress or a new rat in the house that your existing rats can smell.

The rat tail is primarily a thermoregulation and balance organ, but it does carry some behavioural signals.

Tail wagging or vibrating: A rat vibrating or wagging its tail rapidly (sometimes called “tail quivering”) can indicate excitement or mild stress. Context is everything. A tail-wagging rat approaching a new treat is excited. A tail-wagging rat during an introduction to a new rat may be anxious or aroused. Female rats in season may tail-vibrate when their back is stroked.

Tail held high and stiff: Often seen during confrontations or when a rat is asserting dominance. A stiff, raised tail combined with sidling and puffed fur means the rat is in a serious mood.

Tail tucked or dragging: A healthy rat carries its tail off the ground. A rat dragging its tail or letting it hang limply may be exhausted, unwell, or injured. Check for swelling, kinks, or wounds.

Tail pulling: If a rat grabs another rat’s tail during play, the grabbed rat will usually whip around in protest. Tail-pulling is generally considered rude in rat social etiquette and the puller will often receive a telling-off.

What to do: Tail signals are secondary to ear, fur, and vocalisation cues. Use them to confirm what you are already reading from other body language. A stiff tail combined with puffed fur and flat ears is more concerning than a stiff tail on an otherwise relaxed rat.

Most body language signals are normal communication. Some, however, indicate a health problem that needs professional attention.

Head tilt: A rat holding its head persistently to one side likely has an inner ear infection or, less commonly, a pituitary issue. This needs veterinary treatment , it rarely resolves on its own.

Circling or spinning: Related to head tilt. The rat may walk in circles or seem unable to move in a straight line. Same cause, same urgency.

Audible breathing: Healthy rats breathe silently. Any sound you can hear , clicking, wheezing, rattling, snoring while awake , indicates a respiratory problem. Rats have delicate respiratory systems and infections progress quickly.

Persistent porphyrin: Heavy red-brown staining around both eyes and nose that does not clear within a day or two. This is a reliable general indicator that something is wrong.

Sudden aggression in a previously gentle rat: Pain and hormonal tumours can cause personality changes. A rat that was always friendly and suddenly starts biting needs a vet check, not behavioural correction.

Lethargy and isolation: Rats are social and active. A rat that separates from the group, stops eating, or sits hunched and unresponsive is unwell. Rats hide illness instinctively, so by the time you notice lethargy, the problem may already be advanced.

Weight loss: Weigh your rats weekly. Gradual weight loss that you cannot see but can measure is often the earliest detectable sign of chronic illness. A kitchen scale accurate to 1g is sufficient.