General: The House Mouse (Mus musculus), or European House Mouse, is native to Europe. This is a pest species that was introduced all around the world back in the early days of worldwide exploration when European mice and rats were carried on sailing ships. As such, these mice are well naturalized to urban environments everywhere. House mice occasionally can be found in native environments, but usually are associated with humans.

Around Las Vegas, look for House Mice in urban environments and probably places like the Las Vegas Wash.

Head and Body: To about 3-1/2 inches long. Fur gray-brown, short; about the same color on the back and belly.

Tail: To about 3-1/2 inches long. Little hair; appears scaly; about the same color on the top and bottom.

Ears: Short and rounded.

Weight: 1/2 to 1 oz (to about 22 g).

Comments: House mice are prolific breeders. Females can begin breeding at about 6 weeks of age. Gestation is about 3 weeks, litters to about 10, and they can breed all year.