"Rodent" refers to an large order of mammals known for their big, gnawing front teeth and chewing side teeth. Several species are found in California. Some live in the wilderness, naturally integrated into their environment. Others live in or near cultivated and urban areas, making pests of themselves by eating crops and gardens, damaging lawns and buildings and stealing food supplies.
Norway rats, also called brown rats or sewer rats, are found wherever there are people. They live in burrows they've lined with fibrous materials such as paper or cloth. Their burrows are typically found near woodpiles, trash heaps, damp areas in the garden and building foundations. Norway rats aren't particularly good climbers, so if they get in your house, they usually remain on the ground floor or in the basement. They are recognized by their large size, grayish-brown fur, scaly pink tail, relatively small ears and blunt muzzle.
Roof rats, or black rats, are smaller than Norway rats. Agile climbers, they live in trees, shrubs and dense vegetation. When they get into buildings, they tend to live in ceilings, walls, attics and cabinets. They prefer warm climates and are not found in as many areas as Norway rats. However, the two species do sometimes share the same habitat. Black rats have dark gray fur, gray to white bellies, pointed muzzles, large ears and scaly tails that are longer than the rat's body and head combined.
Voles -- also called meadow mice -- are small rodents found in areas with dense vegetation. Although occasionally seen scurrying about above ground, voles spend most of their time in burrows. Their presence in an area is given away by grass covered trails, called runways, that connect burrow openings. Voles are mouse-like creatures with compact bodies, short legs, short furry tails and blackish-brown to grayish-brown fur. Unlike mice, voles rarely enter homes but prefer wild land with good ground cover.
Their are four species of tree squirrels found in California: western gray squirrels; eastern fox squirrels; Douglas squirrels; and eastern gray squirrels. Tree squirrels are active during the day, primarily live in trees and don't hibernate in the winter. They feed on seeds, acorns, nuts, fungi, insects, eggs and young birds. They make pests of themselves by feeding on crops, caching their food in lawns and gardens, gnawing on telephone cables and chewing into buildings.
Kangaroo rats are small jumping rodents found in deserts throughout Mexico and the Southwestern U.S. There are 20 to 22 species, many found in California. They have large heads, big eyes and long tails that may be longer than the head and body combined. They have extremely long back legs, which they use to leap like a kangaroo. They are nocturnal creatures, so they stay in their burrows during the heat of the day and forage for food at night, sometimes letting their food dry in shallow pits before bringing it into their burrows.