will prevent the winter enemies of the beaver from breaking into the house.
Each autumn beaver pile up near by the house, a large brush-heap of green trunks and limbs, mostly of aspen, willow, cottonwood, or alder. This is their granary, and during the winter they feed upon the green bark, supplementing this with the roots of water-plants, which they drag from the bottom of the pond.
Along in May five baby beaver appear, and a little later these explore the pond and race, wrestle, and splash water in it as merrily as boys. Occasionally they sun themselves on a fallen log, or play together there, trying to push one another off into the water. Often they play in the canals that lead between ponds or from them, or on the "slides." Toward the close of summer, they have their lessons in cutting and dam-building.
A BEAVER-HOUSE
Supply of winter food piled on the right
A beaver appears awkward as he works on land. In use of arms and hands he reminds one of a monkey, while his clumsy and usually slow-moving body will often suggest the hippopotamus. By using head, hands, teeth, tail, and webbed
feet the beaver accomplishes much. The tail of a beaver is a useful and much-used appendage; it serves as a rudder, a stool, and a ramming or signal club. The beaver may use his tail for a trowel, but I have never seen him so use it. His four front teeth are excellent edge-tools for his logging and woodwork; his webbed feet are most useful in his deep-waterway transportation, and his hands in house-building and especially in dam-building. It is in dam-building that the beaver shows his greatest skill and his best headwork; for I confess to the belief that a beaver reasons. I have so often seen him change his plans so wisely and meet emergencies so promptly and well that I can think of him only as a reasoner.
I have often wondered if beaver make a preliminary survey of a place before beginning to build a dam. I have seen them prowling suggestively along brooks just prior to beaver-dam building operations there, and circumstantial evidence would credit them with making preliminary surveys. But of this there is no proof. I have noticed a few things that seem to have been considered
by beaver before beginning dam-building,—the supply of food and of dam-building material, for instance, and the location of the dam so as to require the minimum amount of material and insure the creation of the largest reservoir. In making the dam, the beaver usually takes advantage of boulders, willow-clumps, and surface irregularities. But he often makes errors of judgment. I have seen him abandon dams both before and after completion. The apparent reasons were that the dam either had failed or would fail to flood the area which he needed or desired flooded. His endeavors are not always successful. About twenty years ago, near Helena, Montana, a number of beaver made an audacious attempt to dam the Missouri River. After long and persistent effort, however, they gave it up. The beaver may be credited with errors, failures, and successes. He has forethought. If a colony of beaver be turned loose upon a three-mile tree-lined brook in the wilds and left undisturbed for a season, or until they have had time to select a site and locate themselves to best advantage, it is probable that the location chosen will