Rats are funny and intelligent pets. They love company very much, so if you do not have enough time for daily communication with your pet, they recommend starting a pair at once.
If you are not going to breed rats, do not have a female and a male at the same time. Considering how quickly they breed, and how difficult it is to get an ordinary mongrel rat into good hands, in five to six months you will have a whole rat farm, which will cause a lot of problems. Or you will be forced to hand over your pets to feed reptiles. It is best to have two females. Determining the sex of a rat is not difficult, starting from one and a half months.
If your rat is already an adult, you can even distinguish a boy from his appearance. Males are larger and thicker. Their body is shaped like a pear. Females are smaller and more graceful. Their fur is much softer and resembles a mink. Girls are more active and curious. The boys are calmer. Under the tail of an adult male, two shaped, oblong testicles, slightly smaller than an acorn, are clearly visible.
To determine the sex of a small rat, lift it by the tail. By the way, it is possible to take a rat by the tail only in extreme cases, this is quite a lot of stress for the animal. Secure the animal with your other hand, gently holding it by the skin above the ears. This will prevent the little rat from spinning, and you will be able to examine it closely.
Pay attention to the distance from the tail (anus) to the opening of the urethra. For girls, they are located next to each other. The distance between them does not exceed 2 millimeters. For boys, this distance is much greater - about half a centimeter. Compare several pups to determine their exact gender. If you have only one rat and you find it difficult to determine its gender, you will have to wait 2-3 months until secondary sexual characteristics become apparent (see the second step).