Eagle Pest Control, Inc.

Common Rodents in Texas

House Mouse

The house mouse, Mus musculus, found throughout the
world, is the most familiar of the mice; many of its species
live commensally with humans and are serious pests, while
others live in the wild. It usually measures about 6 in. (15
cm) long and weighs under 1 oz (28 grams). It has gray to
brown fur, large rounded ears, a pointed muzzle, and a
naked scaley tail. An omnivorous feeder, it causes great
destruction and contamination of food supplies. Its nests
are built of available chewable materials, such as clothing
and paper. It may carry human diseases, such as typhoid
and spotted fever. Females produce litters of four to eight
young after a gestation period of three weeks; under
favorable conditions they breed throughout the year. The
young mature in two months. House mice, particularly
albino strains, are extensively used in biological and
medical experimentation and are also sometimes kept as


The rat, name applied to various stout-bodied rodents,
usually having a pointed muzzle, long slender tail, and
dexterous forepaws. It refers particularly to the two species
of house rat,
(See comparison chart below) Rattus norvegicus,
the brown, or
Norway rat (See Image below) and R. rattus, the
Black roof rat, (See image below) or Alexandrine, rat. Both
species originated in Asia, but have spread throughout the
world, mostly on board ships. The black rat was common in
Europe in the Middle Ages and was responsible for the
spreading of plague. It has since been largely displaced in
cooler regions by the brown rat, which reached Europe early
in the 18th cent. and North America by 1775.

Rats live mostly in and around human settlements, where
they have few natural enemies and an abundant source of
food. They invade food supplies and cause widespread
destruction. (
See image below) Rats are omnivorous,
aggressive, intelligent, adaptable, and extremely fecund.
Females produce as many as 8 litters each year with as
many as 20 young per litter. The gestation period is three
weeks, and the young reach sexual maturity in about two
months. Rats may live as long as four years. They are
social animals but sometimes fight among themselves.

Although these rats are preyed upon by a number of animals
including the spotted skunk and the barn owl, as well as
house cats, these predators often are not able to keep the
rat population in check. Considerable destruction of
property and foodstuffs can take place where rats are
abundant. In addition, they constitute a menace to public
health. They are known to be reservoirs of bubonic plague
(transmitted to man by the bite of a flea or other insect),
endemic typhus fever, ratbite fever, and a few other dreaded
diseases. Because of this it is commonly said that Norway
and roof rats are more dangerous than lions or tigers! Every
effort should be made to
exterminate them when they are
found on your premises, and it is advisable to ratproof
garbage cans and all buildings to prevent their entrance.

Rodent Identification Chart

Comparison Chart

    Norway Rat                              Roof Rat                    

Rodent Damage
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