SquirrelRodents are placental mammals that have four teeth, known as incisors, which grow constantly.

Every rodent has two incisors in its upper jaw and two its lower jaw. Rodents must continuously gnaw at things to keep their teeth from growing too large.

There are over 2000 species of rodent. There are more rodent species than species of any other type of mammal. Rodents make up 40% of all mammal species.

Rodents can be found on every continent except Antarctica.

CapybarasWhile many rodents are small, the capybara, the largest living rodent on Earth, can weigh more than 100 pounds.

African pygmy mouseThe African pygmy mouse and the pygmy jerboa, two of the world's smallest rodents, weigh less than half an ounce.

You can find out more about different kinds of rodents by clicking on the links below.

1 African Ground Squirrel Marcia Malory 1327
2 Bank Vole Marcia Malory 1545
3 Beaver Marcia Malory 1178
4 Blesmol Marcia Malory 1034
5 Cane Rat Marcia Malory 1243
6 Gambian Pouched Rat Marcia Malory 1210
7 Gerbil Marcia Malory 1094
8 Gray Squirrel Marcia Malory 1387
9 Hamster Burrow Marcia Malory 1187
10 Harvest Mouse Nest Marcia Malory 1286
11 Hazel Dormouse Marcia Malory 1205
12 Marmots Marcia Malory 1036
13 Muskrat Marcia Malory 1209
14 Pocket Gopher Marcia Malory 1404
15 Prairie Dogs Marcia Malory 1068
16 Tuco-tuco Marcia Malory 1517
17 Wood Mouse Marcia Malory 1252