A plump-bodied rodent, the African swamp rat has a rounded, volelike head and small ears. Characteristic features are the grooves on each side of the incisor teeth. Active day and night, this rat feeds on seeds, berries, shoots, and grasses. It will enter water readily and even dive to escape danger. Its nest is usually above ground and is made of plant material, although in some areas swamp rats make use of burrows discarded by other species. Young females reach sexual maturity at 10 weeks of age, males about 3 weeks later. Although swamp rats seldom damage crops, their parasites do transmit tick-bite fever and possibly bubonic plague. Swamp rats are an important food source for many larger predators.