The northern grasshopper mouse, or killer mouse (Onychomys leucogaster), is a North American carnivorous rodent of the family Cricetidae. It ranges over much of the western part of the continent, from central Saskatchewan and central Washington to Tamaulipas in northeast Mexico.The northern grasshopper mouse is found in North America, but primarily in dry areas. They are similar in body size to other mice; on average they are 164 mm (6.5 in) long and about 35 g (0.077 lb) in weight. The tail is most often less than 30% of the total body length, whereas other mice tend to have longer tails adding to long body lengths. The grasshopper mouse is a reddish-black/grey color with white hair on the belly. Unlike most rodents, this one has a carnivorous diet mainly consisting of small insects, other mice, and even snakes. This rodent is also nocturnal, unlike most of its kind. Throughout the night, the grasshopper mouse makes high-pitched noises to claim its territory.