Remember you are much bigger than the mouse and an untrained mouse will be frightened of you. Be gentle and calm when interacting with mice. Alternatively, you can train your mouse to crawl into your hand. Use treats to coax them into your palm. However, if this is your first time, it may take a while before your mouse trusts you enough to eat off of your hand.
It’s important to lift the mouse at the base of its tail and never to have all of its feet in the air. Have at least the mouse’s two front legs touching a surface, such as a cage or your hand. If you hold the mouse by its tail and let it hang, you risk the chance of breaking its tail or even snapping its back. You don’t want to harm the mouse or cause it any pain. Pinkies, or newborn mice, can get cold very fast. Only handle them for brief periods of time. They are also extremely fragile so avoid lifting them by the tail.
It is helpful to compare multiple mice of the same age side-by-side until you are able to see a difference in distances.
A male mouse has a genital area much farther away from the anus than a female mouse. You can also look for testicles when you do this. Although mouse testicles are not as prominent as a dog’s, they do still appear as 2 elongated swellings in the groin region. The testicles will appear large in comparison to the mouse’s body, but the mouse may also draw them up during times of stress.
It can be difficult to spot nipples on pinkies but with good lighting and an observant eye, you can spot nipples as early as three days after birth. Be aware that male mice lack nipples entirely, so this is a good way to identify whether a mouse is male, too. [6] X Trustworthy Source PubMed Central Journal archive from the U. S. National Institutes of Health Go to source
The nipples may also take on a pink, rosy appearance when a mouse is pregnant. This is known as “pinking up” and it is a common sign of pregnancy, but it can be hard to spot.
You could also try placing the mouse on a sheet of glass or in a glass cage. Offer the mouse some treats to keep it still and check for its testicles from the under the glass.
