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western harvest mouse

western harvest mouse (Reithrodontomys megalotis)
Photo © G. C. Rinker, Mammal Images Library of the American Society of Mammalogists

Features and Behaviors

The western harvest mouse has a small (two and three-fourths to three inches) body with red back fur. The belly hairs are gray with a white tip. This mouse has grooved upper incisors. The tail is shorter than the head-body length. The tail is dark on the top, light on the bottom and has very little hair.

The western harvest mouse may be found in the northern one-half of Illinois. It lives in grassy or marshy areas with some taller weeds and brush. It may be more common in areas that are regularly burned. The western harvest mouse eats insects, spiders and grass seeds. It is nocturnal. Mating occurs from March through September. Young are born in a nest made of grasses that is built in other grasses. Litter size is about four. Young are born hairless and with the eyes and ears closed. A young female becomes mature at four months of age.

Illinois Range


Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Cricetidae

Illinois Status: common, native