Why Do Pet Rats Pee Everywhere? The Ultimate Urine Guide

For the most part, everything has gone well since you brought your pet rats home. They’ve adjusted readily to their new surroundings, they’ve made themselves at home in their cage, the pair get along swimmingly, and they seem to be warming up to their new owners, too.

Maybe you’ve even begun to teach them tricks or to recognize their names and come when called. You would like to say it’s going well… Except for the peeing. It’s everywhere, no matter how much you wash or tidy up, there are little droplets all around!

Why do pet rats pee everywhere? Rats have a well-known tendency to pee on pretty much everything. The reason they do so is due to a thing called chemical communication. Urine contains a lot of details about the rat who left it there such as gender, age, sexual availability, and other characteristics.

From one rat to another, this is the equivalent of small talk and can help determine which rats are in the area. As rats are an incredibly social species, the need for this type of communication is high to help establish their hierarchy.

Another use for urine markings is to help identify their environment; what belongs to them, where have they been, which route did they take to get here, and if there are any food stocks nearby that have been given the thumbs-up from the local rats.

Read on if you’re interested to learn more about this quirky form of communication.

Exchanging Info

Markings are to a rat as post-it notes are to a human. Placed along paths, around food, or on their mates, there’s no place off-limits. Exactly how can urine contain this much information, and what all can be communicated from one rat to another with nary a peep?

There are two main types of marking: environmental and conspecific, but they share a multitude of traits. Markings appear to be highly contextual and often contain an overlapping of different factors. In the end, the scent marking is evaluated by the receiving rat and these findings are used to generate either a physiological or behavioral response.


Hormones secreted in the urine will help the next rat identify which sex of rat just passed through. Females will do most of their marking the night before ovulation, following their 4-5 day cycle; this is affected by estrogen and progesterone.

Male rats mark most frequently, with intact adults taking the lead, a behavior that correlates with testosterone levels. Males have a proclivity of marking numerous females and being less selective about the process. Neutering will likely reduce the amount of marking males perform, but it’s doubtful to remove this behavior entirely.


Rats are able to tell whether the owner of the scent marking was a juvenile or an adult rat based on the composition of the urine. Prior to puberty, rats don’t put nearly as much effort into urine markings. This is a behavior that develops with sexual maturity, and it’s most rampant in aggressive, intact males.

Sexual Availability

Females complete most of their markings the night before they go into heat. In doing so, the female rat communicates her sexual availability and uses said markings to draw prospective males to her. Prior to this, females will usually mark the males they like in the days leading up to ovulation. This may be used to give a hint to the rat with a particularly good chance of mating.

General Health

Like most beings, urine is a good indicator of general health as it’s part of our waste management system. Changes in color, scent, or clarity can hint at what’s going on inside the body. To a rat, this may make or break the deal on whether you wish to rear a litter with a prospective mate, as health is a vital trait when considering producing young.

Stress Levels

Nothing like the smell of stress in the morning. Yes, that’s correct, rats can tell how stressed out their pals are by how their pee smells. Stressful scent markers may be used as red flags to warn other rats that something is amiss.

Territory and Ownership Rights

Not only are markings used by new rats, but even the rat who left the markings will put them to good use. A rat will mark their belongings, food, cage furniture, owners, other rats, and many other things they deem to belong to them.

This works in a couple of ways:

  • A place that smells like you will smell familiar, and you’ll feel safe returning. When a rat recognizes their scent markings, they’re reassured they’re in a safe space, and that they’ve been here frequently enough to not have to worry.
  • A rat will always know where they’ve been because they’ve likely been dribbling the whole way there. These routes can then be followed back home.

Other Characteristics

If rats find food that doesn’t harm them when consumed, they will scent mark it. This scent mark attracts other rats and lets them know the food there is safe and has been enjoyed by other rats, too.

Rats will also urine mark each other as a sign of companionship and acceptance. In studies, it has been found that the urine of a juvenile rat is an attack deterrent, not only for themselves but also when the urine was dabbed on adult males.

Many things have been found to have some effect on the communicative value of the urine, but conclusive answers haven’t always been found.

What Causes Pet Rats to Pee More?

Adult rats leave drops of pee everywhere they go, but dominant males are more notorious for this behavior. Should there be a female around, this marking may worsen, especially if the rat hasn’t yet been neutered as the fluctuations in testosterone contribute to this behavior.

Rats are also more likely to urine mark in new areas or unfamiliar territories, and especially if they smell a new rat in the vicinity.

A rat that hasn’t been well socialized may be extremely skittish and frightened when first picked up, your rat could produce a large amount of pee or liquidy poo at this time due to stress. This won’t be a regular reaction and your rat will start to settle in your company as you start to spend some regular time together.

How Much Can Pet Rats Pee?

This will vary from one rat to the next, depending on how much activity they’re getting, but a rat can potentially pee every few minutes. It’s unlikely for a rat to urinate large amounts at one time unless they’ve just woken up from a deep slumber.

A full bladder would likely equate to a tablespoon of liquid, give or take.

That being said, a rat is much more likely to simply pee as they need to; letting out little trickles here, there, and everywhere to update their environment with the latest data.

What Color Should the Urine Be?

Rat urine is similar to human urine when it comes to color; typically, it will vary between shades of yellow. The more dehydrated the rat is, the darker the urine. An active rat who drinks a lot of water is going to end up passing more, resulting in paler urine. This is normal. If your rat is drinking excessively but not urinating, that could be a sign that something is wrong, and you should seek the help of a vet.

There are a few indicators that something is amiss. Learn to look and watch out for:

  • should be monitored, as it could mean that your rat isn’t drinking enough water, or that something has gone awry.
  • is usually a sign of infection, either reproductive or urinary. It’s important to take your rat to the vet and receive the appropriate antibiotics. Infections like this, if left too long, can prove fatal to the rat.
  • is a common sign of blood cells in the urine. This points towards an injury somewhere along the urinary tract. While it’s possible this is only external and caused by a harmless scratch, should the urine remain red for longer than 60 minutes, call the vet. There could be damage to the bladder or kidneys, which will require emergency medical intervention to correct.


Ultimately, this comes down to the social structure that a rat lives within. Rats are highly territorial creatures and, as such, they need a good way to stake out their property. Not only that but whoever tends to mark the most owns the most, which is important when you live in a hierarchal society as the rat does. Even the bed? Especially the bed!

One thing is certain: urine is important to rats. It communicates a lot about identity, safety, social cues, and where a rat stands in their world. While it may not be the most pleasant thing for us, it couldn’t be more normal for our rats, and it can help us understand our pets more if we know why they do the things they do. Urine markings are one small way for a rat to make their home in this big world. Understanding the monumental role these markings play in a rat’s life can help reinstill compassion for when you spot a fresh trickle of pee on that shirt you just washed.

Related Questions

Why does my pet rat pee or poop on me? If this is a large amount of urine or liquid poo then your rat may be scared. Just like horses and other animals, when rats are faced with a life or death moment, or what may be perceived as one, urination and defecation is a way to lighten the load readying themselves for the fight or flight response. It’s an unconscious reaction from fear and isn’t any different to a human reaction to fear.

Darren Black

I'm Darren Black, the owner, and author of AnimalKnowhow.com. I am from Scotland, United Kingdom and passionate about sharing useful information and tips about properly caring for an animal's wellbeing.

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