Color: Varied, but usually light brown to dusty gray on top, light gray or cream on belly.

Droppings: Adult droppings are 1/8-1/4 in (3-6 mm) long, and are rod shaped with pointed ends, but without ridges.

Where found: Probably from central Asia, but now all over the world and throughout the U.S. 

Comparison with other rodents: Adult Norway rat, roof rat and black rat are larger than the house mouse, with a body+head length of 7-9.5 in (18-25 cm) and weigh 7-18 ounces or more. Young Norway rat, roof rat and black rat have head and feet that are extra large for body size. Deer mouse and white-footed mouse have tails that are tawny brown above, white below. Most other native rats and mice have hairy tails, or if not, their tails appear to be made of ring-like segments.

Habitat: Dark, secluded places with little disturbance and plenty of nesting material, such as paper, fabric, insulation, packing materials, cotton.

Food: House mice eat many kinds of food, but especially seeds. Main feedings are at dawn and dusk. They get moisture from their food, but will take water also, especially when eating protein. They prefer sweet liquids.

Biology: Mice are social. Related male and female house mice are compatible, but unrelated males are aggressive. Small sized territories, marked with urine, are maintained by a dominant male, with lower-ranking males and females. Mature house mice are aggressive towards strangers of either sex. They mature in 35 days, and live about 1 year, but can survive to 6 years. Pregnancy takes 18-21 days, with 5-8 young per litter, 8 litters per year, and 30-35 mice are weaned per year. A female can have a litter every 40-50 days, so more than 1 litter may be in the nest at a time. They see clearly only 6 inches ahead, and are color blind. They climb, run up rough walls and along pipes, ropes, and wires, jump 12 inches high and down from 8 feet, and sometimes swim. They can survive in 14 degrees F (-10 C). 

Damage: The house mouse gnaws objects, eats and contaminates stored food, and transmits disease by droppings, urine, bites, and direct contact, or contact with cats, fleas, mites.

Invasion: An opening larger than 1/4 in (6mm) permits a house mouse to enter a structure.

How to detect and control house mice:

Detection:

• Droppings indicate a feeding place.
• Front 4-toed print is in front of 5-toed hindprint.
• Rub marks are smaller than rats' rub marks.
• Active runways are free of cobwebs and dust.
• Fresh droppings are soft and moist. New gnawings are rough.
• They burrow in insulation.

Control:

• Territories have 20 feet or less diameter. If trap is untouched in 48 hours, they're gone.
• Put a little bait in many stations to find out food preferences.
• Move things when placing traps or bait stations so they will explore.
• Since they nest near their food, use nesting material on traps or glueboards.
• In hot or dry weather, or near a dry food source like grain, use liquid bait.
• Use foods such as prunes, fresh pineapple, salted peanuts, or whatever they have been eating.
• Outdoors, reproduction is low in October-January, so this is a good time to control.
• Do not use bait stations with rodenticide in your home. Dead rodents in walls can cause odor problems and future fly or dermestid beetle infestations.

Copyright 2005: Braveheart Pest Control