Rodents

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 program.