If you are planning on getting a rat or you just got one as a pet, you probably have many questions about their behavior. And among the most common ones are whether a male rat will spray on you or around your home.
So, do male rats spray? Yes, male rats do spray, more so than female rats. Adult male rats that haven’t been neutered spray the most. They will spray a small amount of urine — just a few drops — on objects and other rats. This is the way they communicate, and their urine contains plenty of information about them.
Urine marking is a characteristic in many animals across the globe, and rats are no exception. However, there are specifics to the urine marking in rats that is unique to them, and if you’re about to become a pet rat owner — or you have one already — you should know them. Read on to find out more about urine marking in rats.
What is Urine Marking?
Urine marking, or spraying, as it’s commonly called, is a small amount of urine sprayed or smeared on objects or other animals. For rats, it’s a way of talking and communicating their identity. Other rats can discern a lot of information from those marks, including:
- Their age
- Their sex
- Their species
- How reproductive they are
- If they are available sexually
- What their social status is
- How stressed they are
The urine reveals even more. When one rat drops this chemical signal, a different rat will be able to pick it up and create a response to it.
Urine-Marking And Rats
When it comes to rats, both male and female ones spray. However, males will always spray more than females. An adult rat will make more of these marks than a baby rat, and a rat that hasn’t been neutered will spray more than the one who has been.
A female rat will spray when they are in heat, every 4 to 5 days, most likely when they ovulate.
Rats will spray on anything that they can easily access, including other rats in your home. They will likely spray on new smells and over urine that came from other rats.
This spraying happens because of hormones. For example, female rats will mark the most just before they ovulate, and this is related to estrogen as well as progesterone. At the same time, male spraying relates to testosterone. Male rats will mark the most when they are in puberty. Of course, spraying can be reduced by castrating them.
Spraying serves different purposes:
- Attracting rats of the opposite sex — it acts as a signal of sorts, that they are there and ready
- Labeling the environment that they live in to make it more familiar and comfortable to them
- Making new things more familiar, such as new scents, a new arrangement of furniture, etc.
- Urine-marking could also possibly be a way to mark the territory to keep other rats away from that area, but the research there is mixed, and it’s yet to be determined whether this is true or not.
- Females that are not in heat yet will mark male rats that they select for their preferred mating buddy.
There are also a few interesting characteristics of marking between rats:
- Male rats that are castrated mark less
- Dominant rats mark more than other rats in the group, and they mark their subordinates
- The subordinate rats mark those rats below them in the hierarchy more than they mark the dominant rat
- Female rats and those that are not adults yet mark each other in small amounts, but steadily.
How Do Rats Spray?
Rats spray or urine mark when they smear a bit of urine on something in their environment. The urine deposits are sometimes applied with a discharge from their sebaceous glands.
They spray as they pass the objects or rats. In essence, the rat is rubbing their genital area on something, lifting their back leg, and passing it over an object. A small amount of urine is left behind. If a rat is spraying on another rat, they will crawl over them.
These movements are all quite discreet — so much so that you’ll barely notice it. Especially so if the rat in question is male, their back will arch, placing their genitals slightly lower, and they will pause for just a second to spray.
Then, another rat will receive this signal and respond to it through their behavior or in a different, physiological way. The relationship between the rat that sprayed and the rat that receives this signal is a part of the natural selection — for instance, a urine deposit will attract a rat of the opposite gender. This benefits both parties.
A urine deposit contains information that is available to the receiver of the signal. As mentioned, the receiver will be able to tell the age, species, and sex of the other rat, their reproductivity, and how familiar they are to them, their identity, social status, how stressed they are, etc.
Where Will Your Rat Spray?
Rats spray on things that they can easily pass their leg over. So, the object will have to be accessible to them and be short enough. They will mark and spray more if you introduce them to a smell that’s strange to them. If you move your furniture around, they will mark them again to create familiarity.
They will not mark an environment that’s new to them. When you get your pet rat, they will wait for a few days to get to know your environment, and then they will spray.
If you had a rat before or you already have one, your new rat will mark over the other rat’s marks, especially if you had a rat of the opposite sex to them. They won’t mark over their own urine.
They’ll also mark their food, especially the ones they like the most. They do this in order to attract other rats to that food — rats always look out for other rats in the group.
If rats spray on other rats if they are of the same species, you’ll notice that they will crawl over each other and leave a wet area on the back of the other rat. It’s a way they communicate, according to some studies, but the results are not conclusive yet.
You’ll be able to see it more clearly with a black light.
The Causes of Spraying
Females spray every 4 to 5 days in order to attract males — they do it just before their ovulation. So, this type of spraying is caused by hormones. If you want your female rat to stop spraying, you can remove their ovaries.
Male rats spray to attract females, especially during puberty, when they have a lot of testosterone. If you want them to stop spraying, you can castrate them. Of course, they will still spray a bit once in a while, but the amount will be reduced.
Castration reduces environmental markings too.
They will still mark, following environmental signals like seeing smaller objects around them, rearranged objects, etc. They need the optimal odor area in which they will be comfortable. They’ll exhibit less anxiety if they mark the area they spend the most time in. It helps them move around freely and helps them understand where they can move. They use it as navigation of sorts.
So, your male rat will spray. The amount and frequency of spraying will decrease if you castrate them, but they will still spray the objects around them to better understand their territory and feel more comfortable in it.
- Science Direct: Object-directed urine-marking by male rats (Rattus norvegicus)
- Science Direct: Conspecific urine marking in male-female pairs of laboratory rats
- Research Gate: Hormonal control of odor preferences and urine-marking in male and female rats
- NCBI: A new test paradigm for social recognition evidenced by urinary scent-marking behavior in C57BL/6J mice