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 1316
2 Bank Vole Marcia Malory 1539
3 Beaver Marcia Malory 1172
4 Blesmol Marcia Malory 1029
5 Cane Rat Marcia Malory 1239
6 Gambian Pouched Rat Marcia Malory 1205
7 Gerbil Marcia Malory 1085
8 Gray Squirrel Marcia Malory 1379
9 Hamster Burrow Marcia Malory 1181
10 Harvest Mouse Nest Marcia Malory 1282
11 Hazel Dormouse Marcia Malory 1199
12 Marmots Marcia Malory 1028
13 Muskrat Marcia Malory 1202
14 Pocket Gopher Marcia Malory 1401
15 Prairie Dogs Marcia Malory 1061
16 Tuco-tuco Marcia Malory 1507
17 Wood Mouse Marcia Malory 1248