Behaviour Catalogue

While it may seem daunting at first, rat behaviour is actually quite easy to understand with ample examples. Providing adequate care will result in healthy behaviours being exhibted by your rats.

Note: Sources and references are hyperlinked throughout the text and will take you to the original page or paper being referenced.

Common Behaviours

Below are the most commonly-seen behaviours exhibited by rats. Don’t be alarmed if you see any of these. They are completely normal and indicate that you have a healthy rat.

Rats spend an enormous amount of time awake grooming themselves as well as their cagemates. They are fastidious cleaners, and much like a cat you will see them cleaning and scratching themselves throughout the day. Cleaning is also a form of social communication between rats, indicating hierarchy. Rats will oftentimes groom their owners as a sign of affection, since they consider us part of their social circle.

While it may seem odd to us, it is quite normal for rats to sleep with their eyes open. During light sleep, known as their resting state, they are often found with their eyes open despite being asleep. It has been hypothesized that this is due to an adaptation rodents have acquired to increase survival: in the wild, a predator is much less likely to go for an animal who is appears "awake" than one that is asleep. It is more common for rats to sleep with their eyes opened at night than it is for them during the daytime.

Taters having a nap with his eyes open

Rats demonstrate bruxxing and boggling as a way to express contentment and a state of relaxation. They can also do this in times of stress as a coping mechanism, much like how cats will purr when stressed.

Bruxxing: how a rat grinds their front teeth back and forth, creating a “crunching” sound. This is also how rats typically keep their teeth filed down naturally, as their teeth never stop growing.

Boggling: how, in response to bruxxing, rats’ eyeballs will vibrate rapidly, bulging out of the eye socket. This is because rats' lower jaw (the mandible) is separated into two parts

Bruxxing and boggling inside the cage

Thistle boggling after being pet

Video Credit: @listar_rattery on Instagram

Popcorning is the term used to describe the behaviour in which a rat will unexpectedly jump or bounce around. Similar to how dogs get "zoomies" or how rabbits "binky", popcorning is associated with happiness and excitement. You will often see this happening more frequently in younger rats as they have more energy than adults.

Even without vision problems, rats have exceptionally poor vision. They cannot see well and rely on their whiskers and sense of smell for navigating the world around them. In order to focus on an object further away from their field of scent/touch, rats will sometimes sway. This involves a small “scanning” motion with their head as they try to gain a better picture of what is going on. This behaviour is seen more commonly in pink or ruby-eyed rats, who have worse vision than standard black-eyed rats, but is not exclusive.

Female rats have very short oestrus cycles, and go into heat every 4-5 days. As a result, females will display sex-specific behaviours related to their hormonal levels, as this is how they indicate to a male that they are ready for mating. These behaviours are entirely normal and are really only silly to watch from a pet owner’s perspective.

Ear wiggling/vibrating: females will often rapidly vibrate their ears as a sign of arousal.
Mating posture: Females will tilt their head upward and hind end upward, with their middle touching the ground. This can sometimes be triggered if you handle a female rat in heat.
Mounting: While in heat, females can sometimes mount one another.

Appa vibrating her ears in response to being touched
Video Credit: @antares_anta on Discord

Appa exhibiting the mating posture

Video Credit: @antares_anta on Discord

Deciphering Body Language

Alongside common behaviours, rats exhibit subtle body language that can provide us insight into how they are feeling. In fact, rats have been found to display a variety of different facial expressions in response to both positive and negative stimuli. Rats can even “blush” to indicate that they are happy and pleased.

A Brief Guide to Rat Body Language by Maija Karala

The Spectrum of Rat Fear, Anxiety, and Stress (FAS) by FearFree

Aggresion vs Play

Rats love to play fight with one another. They also do this to determine and maintain social hierarchies, which can result in some squeaks of annoyance from the “victim”. However, when a real fight occurs, it is exceptionally explosive and frantic. A true fight is extremely dangerous, resulting in severe wounds and potential fatalities. With that in mind it is important to be vigilant when introducing new rats to one another, and be looking for signs of aggression that may lead to a fight if you do not intervene beforehand.

Playful Behaviour

Boxing: Standing on their hind legs. Accompanied with light "smacking"or freezing in place, holding one another's face
Wrestling: taking turns pinning down one another. It looks dramatic, but body language appears relaxed. The instigator will stop if the other pushes them away
Gentle grooming: after pinning down a playmate, a rat may nibble or groom as a way of maintaining hierarchy
Chasing: running around, as if they are playing tag
Popcorning: similar to how dogs get "zoomies" or how rabbits "binky", popcorning is associated with excitement and playfulness

Video Examples:

Miso grooming Zabu

Video Credit: @hanaverion on Discord

Notice how quickly they swap roles, disengaging when the other is tired

Aggressive Behaviour

Teeth chattering: unlike bruxxing, which is soft-sounding, teeth chattering will be intense and noticably loud
Hissing: rats will hiss much like how cats will
Slapping of tail: tail is whipped around dramatically
Baring teeth: showing of teeth with mouth slightly open, indicating that a bite is imminent
Hair standing on end: puffing of fur outwards to try and appear larger than they are. Often accompanied with an arched back
Side-stepping: A rat will arch their back and walk sideways towards another rat, often pressing up against the other. While not always a sign of aggression on its own, accompanied with other behaviours it is

Video Examples:

Shrimp (Black rat) hissing in response to Miso and Zabu's Presence

A prime example of aggressive fighting

Video Credit: @funkycanine on Discord