In an adult or almost adult male, the testicles are clearly visible at the base of the tail. Click here to see pictures of the different sexes. Gerbils are often mistaken for mice, but there are some clear differences between these two species. Gerbils dig, and mice don't. The gerbil's head is shorter and wider, like a squirrel's head, its hind legs are longer than its front legs, whereas the legs of a mice have a more equal length.
Gerbils also have a long, hairy tail with a tuft at the end, while mice have almost naked tails.
Another difference which is harder to see, is that the upper incisors of the gerbil have a narrow groove at their anterior surface which mice don't have. Speaking about teeth, like in all rodents, the incisors of gerbils never stop growing. By gnawing at things, they keep their teeth short enough to eat properly. A nutmeg gerbil eating some chicory. Please note that the material on these webpages is covered by copyright law.