The prairie beaver (Ricinus canadensis) is a species of large rodent native to North America that can reach a weight of 150 lbs (25 kg) at adulthood. They are known for their habit of constructing long walls from blades of grass that they fell using their minuscule incisors. This is similar to the dam-building behavior of their better-known wetland relatives but its purpose is not known.
Prairie beavers are a highly social species that prefers to live in large colonies, constructing communal "lodges" out of grass for protection from wolves and wildfires. When threatened outside of their lodges they slap their broad leathery tails against the ground, raising a cloud of dust that gives a warning signal to their bretheren. A herd of Prairie Beavers will defend its lodge to the death, with nasty sharp biting teeth. A herd of fully-grown specimens can kill a human.
Although the prairie beaver population exploded after the European colonization of North America due to the devastation of the bison (a herd of bison could devour a prairie beaver lodge in a matter of hours), the prairie beaver's habitat has been threatened in recent years by modern farming practices. As a result legislation has been passed requiring many farmers to place artificial prairie beaver lodges in their fields. These artificial lodges are composed of harvested grasses and straw, bound tightly with twine into rectangular or cylindrical shapes for ease of transport but still capable of providing ample shelter for families of beavers.