Content

• To step
• Method 1 of 2: View the anatomical distance
• Method 2 of 2: Using the nipple method
• Tips
• Warnings

Determining the sex of a mouse is especially important if you are a breeder, keep a lot of mice, or are simply very curious about the sex of your little friend. There are two main methods of distinguishing between male and female in mice, requiring a good eye and gentle handling of the mice. You can determine the sex of a mouse by looking at the distance between the genitals and the anus or by examining whether or not your mouse has nipples. It is always good to know the sex of your mouse so that you can separate the males from the females and avoid unwanted pregnancies.

To step

Method 1 of 2: View the anatomical distance

1. Gently lift the mouse out of its cage. The best way to do this is to gently grasp the base of the tail just enough to slide your hand under its body. Continue to hold the base of the tail as you lift the mouse out of the cage.
   • Remember that you are much bigger than the mouse and an untrained mouse is afraid of you. Never try to scoop it out or pinch it. He could then jump out of your hand and injure himself.
   • You could also train your mouse to crawl into your hand itself. The easiest way to do this is to put your mouse's favorite treats in your hand to get it to sit on your hand. However, if this is your first time, it may take a while for your mouse to trust you enough to eat from your hand.
2. Position the mouse so that you can see its genitals. Hold the mouse by its scruff and turn it onto its back. If that position is not comfortable, just hold the animal in your hand with its rear facing you. Then grasp the base of the tail again and lift the tail so that you can see the genitals well.
   • It is important to grab the mouse at the base of the tail when lifting and make sure that its legs never all lift off the ground at the same time. Make sure that at least the 2 front legs of the mouse touch a surface. If you grab the mouse by its tail and let it hang, you risk breaking the tail or even its back. You don't want to cause injury or pain, of course.
   • Pinkies, or newborn mice, can get cold quickly. Therefore, only pick them up for short periods. They are also very fragile, so it is better to avoid picking it up by the tail.
3. View the distance between the anus and genitals of the mouse. The anus is the opening directly under the tail. Depending on the age of the mouse, it can be quite easy or very difficult to determine the sex.It is very difficult to determine the sex of young mice, because the distance between anus and genitals is almost the same. So don't feel embarrassed if you have determined the gender incorrectly.
   • It can help to compare several mice at the same time until you recognize the difference in the genital distance.
   • In some cases you only have 1 mouse, or the genital distance looks the same in all mice. Then consult a book about mice or search the internet for pictures or diagrams showing the differences between the sexes of mice. Many sources provide visual data on the differences between the sexes at each growth stage.
4. Determine if the mouse is female. The genital area of ​​a female mouse is much closer to the anus. The urethra is usually within 0.5 cm of an adult mouse. From the anus.
   • Females have a vaginal opening behind the urethra, which can look like a bump.
5. Determine if the mouse is male. The genital area of ​​a male mouse is further from the anus than that of the female. You can also see testicles if they hang down. You can distinguish the testicles from the female urethra by looking for a vaginal opening behind the bump.
   • You can also try to determine the presence of testicles. Adult male mice have drooping testicles that are sometimes very easy to distinguish. You may need to be patient, though, as a male mouse can retract its testicles. You can usually see it clearly when the mouse eats while "standing" on the edge of its bowl. The testicles will usually hang down in this position. However, the absence of testicles does not necessarily mean that a mouse is female. You may need to use other methods to confirm the gender of the mouse.

Method 2 of 2: Using the nipple method

1. Position the mouse so that you can see the abdomen. Grab the mouse by its scruff and turn it onto its back in your hand. Nipples can be invisible because of the fur on the mouse's belly. Try to part the coat or gently touch the stomach to discover the nipples. When the mouse is very young, they can look like bald patches.
   • It can be difficult to distinguish nipples in pinkies, but with good lighting and a sharp eye, you can distinguish the nipples from 3 days after birth.
2. Look for the nipples to determine if a mouse is a female. Male mice have no nipples, while female mice have 10 nipples that look like little dents. The most prominent nipples are the two closest to the genitals.
   • Pregnancy is usually an easy visual way of determining sex, as the female's nipples will swell and droop, affecting the hip area. saddlebags are being formed. It will not be obvious in all mice, however, an obese male can look just like a pregnant female. Try to get the saddlebags feeling soft, you may feel internal bumps, which are probably the babies.

Tips

• Determine the sex of your mice as soon as possible. If you have mice that you are not sure of sex, set them aside and try sexing again at another time.
• Do not breed mice older than 8 months. These mice are elderly, so in most cases they die during or after pregnancy.

Warnings

• Do not lift a mouse by its tail. Hold it gently in your hand and handle it gently.
• Never breed with a female more than 3 times.
• If you don't separate the mice based on gender, unwanted pregnancies will occur quite quickly. This is possible from 4 weeks after birth. Pregnancy can be very difficult for a mouse and some females die during childbirth.