Rodents have many special features. All rodents have one pair of upper
and lower chisel-shaped 'incisor' teeth that are covered with hard enamel
on the front and a softer substance like bone on the back. As the rodent
gnaws, the backs of the chisel-shaped teeth wear away faster to maintain
a sharp edge. The incisors grow all of the time or continuously. If the
rodent does not keep gnawing, the front incisors will grow right out of
its mouth and prevent it from eating. The incisors might cause death by
growing inwards into the jaw or skull.
Rodents have no pointed teeth called canine teeth. There is a gap between
the front incisors and the molars. Rodents can curl back their lips out
of the way of the sharp front teeth into the gap between the front teeth.
This leaves the front teeth bare. It makes it easier for the rodent to
gnaw hard food or wood without injuring its mouth. It also helps keep
unwanted wood, nut shells and soil from being eaten along with the food.
Gnawing is not chewing. Gnawing means that the rodent nips off, or shaves
off, layers of food or hard wood. When the food is inside its mouth, it
chews the food into shreds, a paste, or pulp. It does this with flatter
teeth called molars, before swallowing the food.
Some rodents have molars that grow all of the time much like the front
teeth. Still others have powerful jaw muscles that let them chew in a
special circular way that shreds hard fibrous foods better.
Most rodents, but not all, have four toes on the front feet and five
toes on the back feet. Most rodents are nocturnal (awake at night). Rodents,
as a group, are very active and must eat much food. During the winter
when food is scarce, most Ontario rodents hibernate (see hibernation).
Some, such as the chipmunk, store foods and wake from a deep sleep to
eat from time to time.
Small members of the rodent family have more young in a season than any
other mammals. This makes up for the many animals eaten by predators.
The families of wild rodents living in North America include squirrels,
chipmunks, rats, mice, beavers, lemmings, muskrats, voles, and porcupines.
There are more rodents living in North America than any other kind of
mammal. They range in size from mice weighing less than three grams to
the beaver weighing 49.5 kg. Only the capybura of South America is a larger
rodent than the beaver.
Control: The control process of all rodents include
exclusion (sealing holes and openings) habitat modification (sanitation
and elimination of harborage) and control procedures (trapping and baiting).
All three play a crucial role in achieving the desired results of a rodent