Notice the smooth tail, small feet, pointed nose, large ears, and large eyes.

Nests in wall voids, in undisturbed debris, or outdoors.

Eats grains, bird seed, dry pet food, but will eat anything, even soap and leather if no other food is available.

Generally stays within 10-30 feet of nest. Doesn't like open spaces.

The house mouse is identified by a small slender body weighing between 1/2 to 1 ounce as an adult. The ears are large, the tail is semi-naked and is as long as the head and body together. The fur is usually dark gray on the back and light gray on the belly, but many color variations are possible. Albino, black, and mixtures of black and white have been bred in the laboratory. Mice can be identified from young rats by the size of the head and the hind feet.

When living conditions for rodents are very good (plenty of food, water and shelter) rodents can multiply rapidly. However, when living conditions are stressful, overall rodent reproduction and population growth are slowed considerably.

A female produces between four and seven pups per litter following a gestation period of about 19 days. The pups are born blind. Within 7-10 days they are covered with fur; the eyes and ears are open. By the third or fourth week the pups are weaned and begin to take short trips outside of the nest, feeding on solid food and exploring and learning their surroundings.

Notice the scaly tail, large feet, blunt nose, small ears, and small eyes.

Digs burrows along foundations and under debris piles, often found in basements.

Can enter homes through toilet pipes.

Prefers meat and fish, but will eat anything. Very aggressive, strong burrower and excellent swimmer. Large range - may travel 50 yards from nest to find food or water.

The Norway rat is also known as the house rat, brown rat, wharf rat, sewer rat, water rat, and gray rat. The Norway rat is larger, stronger, more aggressive, and better adapted for producing young and surviving in colder climates than other rat species.

The Norway rat has a stocky body, weighing between 12 and 16 ounces as an adult. The body fur is coarse and ranges from reddish to grayish brown with buff - white under parts, but there are many color variations including all black Norway rats. The nose is blunt, the ears are small, close set, and the ears don't reach the eyes when pulled down. The tail is scaly, semi-naked and shorter than the head and body combined.

Breeding peaks for the Norway rat are normally in the spring and fall of the year, decreasing during the hot summer and the cold winter. After mating and a gestation period of about 22 days, the mother rat gives birth to a litter of 8-12 pups. The young are blind at birth. Their eyes open in about 9-14 days, and they are weaned 10-15 days later. By this time the pups begin to take short exploratory trips out of the nest, learning by imitating their mother as to their surroundings, pathways to food, hiding spots, and burrow entrances. The young reach sexual maturity at the age of 3 months, although under good conditions, it may be as early as 8 weeks.

The average female Norway Rat has 4 to 7 litters per year and may successfully wean 20 or more pups annually.