National Geographic : 1955 May
+ Frenzied Digging Bares Grass Roots Leaves, roots, and tough grasses bind the mud in beaver dams and lodges. The animal trowels materials into place with forepaws and nose. Coarse guard hairs emerging from this beaver's dark-brown inner fur lend a cinnamon hue to its coat. © EiKtachromes and iKoaclromes (below) by Wills reterson + Orange Incisors Hew Trees with Ease A beaver must gnaw, else ever-growing teeth prop its mouth open. Lower incisors cut while uppers guide and hold the wood (opposite page). Webbed hind feet (left) make the rodent an expert swimmer; the broad flat tail acts as scull and rudder.