When deciding to buy pet rats, one of the first decisions to make is whether to adopt boys or girls. Rats need to live in pairs or groups, as they are social creatures and don’t thrive living alone. However, unless you are desexing your rats, it is important that these are same-sex, as breeding is not something that should be entered into lightly.
So, how do we choose whether to keep males or females? I’m going to say up front that neither male or female rats are objectively better and I love, and own, them both!
Male rats are known as bucks, and I love them unconditionally, because a good male rat is a personable, curious chonk of affection and intelligence. Female rats, known as does, tend to be smaller and livelier, but if well-handled can be just as cuddly. No one who loves rats will be disappointed by either.
However, as most pet owners need to choose, lets break down some of the characteristics where there are some sex-based differences.
Table of Contents
Male and female rats are different sizes
There is overlap in the adult size of male and female rats, but on average boys are definitely chunkier in all dimensions. Living in the UK and Australia my boys have weighed between 350 and 700 g (0.77 – 1.5 lb), while my girls have been between 200 and 450 g (0.44 – 1 lb). Compared with a pet like mice, both sexes are a comfortable size to handle, but the males definitely offer more to get hold of.
Male rats have big testicles
There is no way to put it delicately: bucks are stacked in the testicle department. Or as my mum put it after spotting Vlad’s backend on Skype “they really do pack a suitcase down there, don’t they?”. The average unneutered male rat has balls that are big, floofy, and, if they decide to climb on your head, definitely in your face. Personally, I’ve got no issue with that – it’s just a body part. However, if you aren’t comfortable with boys showing off their boy bits, buck rats might not be for you.
Do male and female rats smell different?
Yes and no! It depends what kind of smell we’re talking about. Neither have an unpleasant body odor, but intact boys have a more distinct smell if you sniff their fur. Some people compare it to the smell of Doritos! This comes from the oils they naturally secrete in the back fur when sexually mature. These can sometimes be seen as an orange layer on the skin, known as buck grease, and is completely natural. Both sexes have scent glands on their flanks which can release a fluid into the fur that smells a bit like grape soda. However, this only happens when they are feeling territorial.
In terms of cage smell, there isn’t much difference between the sexes. My boys are very well-behaved, use their litter trays, and don’t pee in (or chew!) their beds – although Vlad does like to sleep in his toilet! My girls have no standards whatsoever. However, you’ll easily find owners who say the exact opposite, and that’s because litter training, peeing and pooing is less about the sex of the rat and more about general habit. In any case, whether the cage smells comes down to how we furnish and clean it, rather than what the rats do.
Do male or female rats scent-mark more?
There are two different types of scent-marking commonly seen in rats.
One is “scrubbing” where a rat who is feeling territorial will rub against walls, floors and cage furniture. This involves pressing not only their genitals but also the scent glands on their flanks against the object of interest. It generally only happens during intros, or if the rats move to a new home that smells of strangers. Both sexes do it, but it is more common in hormonal boys – although that said, my current biggest scrubby floofball is Spoddles, who has been neutered for nearly a year! My intact boys don’t seem to care much. So, it is very much down to individual personality as well as sex.
The other type of scent-marking, and the one potential owners tend to be more worried about, is dribbling urine. Again, this is a territory thing and rats do it to mark out objects and humans as their own. Received wisdom says this is a boy problem, as urine marking is most commonly seen in other male animals. However, I’ve not noticed much difference between the sexes. Some rats do it, some rats don’t. My top dribbler at the moment is a middle-aged girl who wants to make it plain she loves me and I am hers. Again, my intact boys have more important things on their minds, like stealing my teabags.
Do male rats bite?
Well-bred rats of either sex should not bite, as temperament is something that good breeders actively select for. A rat with behavioral problems or hormonal aggression should never be bred from, and so those issues should be rare in good breeder lines.
However, if the breeder is not selecting on temperament (for example, where rats are bred en masse), then male rats can often develop hormonal aggression at between 3 and 8 months of age, and this can manifest as biting of either cage mates or humans (or both). In my experience, this is a very common cause of lone boys ending up in rescue. Although some boys do just grow out of it, the simplest solution lies in neutering, which generally resolves the problem in a few weeks. I have taken in so many “aggressive” rescue boys who have turned into complete boingy playful sweethearts after my vet confiscated their testicles.
It’s much less common for girls to bite, and in my experience, usually only happens where they have experienced trauma or poor handling. In the case of both sexes, the best guarantee against biting is adopting well-handled rats from a reputable breeder or rescue.
Are male or female rats more playful?
All baby rats are playful, and there is no obvious difference between the sexes until about 6-8 months. At this age, I’ve found that boys, especially intact ones, do tend to settle down a bit more, and lean toward pootling and contemplating, rather than sprinting about the place at full tilt and climbing where they shouldn’t. Girls often stay very lively well into middle age, and only contemplate slowing down once they hit 18 months plus. So, if boingy playfulness is important to you, does might be your thing.
That said, a lot of behavior is set in the breeding line – some lines will produce playful boys, and others slower does.
Who gives the best cuddles?
Most pet owners like to have a good cuddle with their pets at some point, and rats are excellent, affectionate snuggle buddies. In my experience, cuddliness in rats is more about age, personality, and prior handling than sex – my go-tos at the moment are a 21 month old girl, and a 33 month neutered boy. Received wisdom says that boys are more likely to make cuddly pets, just because they slow down at a younger age. Again though, checking with the breeder about the temperament of their lines is the best way to find a pet who will suit you.
Do you prefer male or female rats? Let us know in the comments below!