You might not know if you have a male or female mice.Sexing is the process of determining what sex is.Both methods of determining sex require gentle handling of mice.The distance between the mouse's genital area and anus is known as the anogenital distance.If the nipples are visible, sexing young mice is a good idea.The best way to prevent unwanted pregnancies is to know the sex of your mice.
Step 1: Lift the mouse with 2 hands.
Use both hands to scoop up the mouse as you form a cup.If you want to support the hind legs of a bigger mouse, you can place one hand under the chest.An untrained mouse will be frightened of you because you are much bigger.When interacting with mice, be gentle and calm.If you train your mouse, it will crawl into your hand.You can use treats to get them into your palm.It may take a while for your mouse to trust you enough to eat off of your hand.
Step 2: The mouse should be placed on its back to see its genital area.
Turn the mouse on its back by taking it by the scruff of its neck.If it doesn't feel right, hold the mouse in your hand and look at it.If you want to see the genitals, lift the base of the tail.Lift the mouse at the base of its tail so that it doesn't have all of it's feet in the air.The mouse's two front legs should touch a surface, such as a cage or your hand.If you hold the mouse by its tail, you risk breaking it or snapping it back.You don't want to hurt the mouse.Babies can get cold very quickly.Only handle them for a short period of time.They are very fragile so don't lift them by the tail.
Step 3: There are distances between the anus and the genitalia.
The anus is under the tail.It can be difficult to have sex with a mouse that is older.Young mice, especially newborn pinkies that have no fur, are very difficult to sex and the anogenital distances between sexes can almost look the same, so don't feel silly if you sex them wrong.It just takes practice.It's helpful to compare multiple mice of the same age side by side until you can see how far apart they are.
Step 4: Sex is determined by distance.
The genital area of a female mouse is closer to the anus.The vagina is usually small on an adult mouse.Females have a vaginal orifice behind the urethra.A male mouse has a different genital area than a female mouse.When you do this, you can look for testicles.Although mouse testicles are not as prominent as a dog's, they still appear as 2 swellings in the groin region.In comparison to the mouse's body, the testicles appear large, but may also be drawn up during times of stress.
Step 5: To identify a female, look for prominent nipples.
Young female mice have more prominent nipples than males.The mouse should be placed on its back to view its stomach.Take the mouse by the scruff of its neck and place it on its back in your hand.There is fur on the mouse's stomach.Feel the belly to see if you can see the nipples.If the mouse is young, they may look like bald spots.You can spot nipples as early as three days after birth with good lighting and an eye.It's a good idea to know whether a mouse is male or not because male mice don't have nipples.
Step 6: There are signs to identify an older female.
The nipples will swell and drop, forming "saddlebags" around the hip area.Some obese males may look like pregnant females, and not all mice will be as obvious.When a mouse is pregnant, the nipples may look pink.Pinking up is a common sign of a pregnant woman, but it can be hard to spot.
Step 7: To identify a male, look for small bumps near the scrotum.
Adult male mice have testicles that are easy to see.You may have to be patient in order to get a look because a male mouse can withdraw his testicles.One way to get a good look is to wait for the mouse to eat while standing on the rim of its food bowl.His testicles will descend most of the time.There are small balls near the scrotum.You can place the mouse in a glass cage or on a sheet of glass.Check for the mouse's testicles under the glass and give it some treats to keep it still.