The Builders. 93 



is roofed by stout sticks arranged as in an Indian 

 wigwam, and the whole domed over with grass, 

 stones, sticks, and mud. Once this is solidly frozen, 

 the beaver sleeps in peace ; his house is burglar 

 proof. 



If on a lake shore, where the rise of water is never 

 great, the beaver's house is four or five feet high. On 

 streams subject to freshets they may be two or three 

 times that height. As in the case of the musc|uash 

 (or muskrat), a strange instinct guides the beaver as 

 to the height of his dwelling. He builds high or low, 

 according to his expectations of high or low water ; 

 and he is rarely drowned out of his dry nest. 



Sometimes two or three families unite to build a 

 single large house, but always in such cases each 

 family has its separate apartment. When a house 

 is dug open it is evident from the different impres- 

 sions that each member of the family has his own 

 bed, which he always occupies. Beavers are exem- 

 plary in their neatness ; the house after five months' 

 use is as neat as when first made. 



All their building is primarily a matter of instinct, 

 for a tame beaver builds miniature dams and houses 

 on the floor of his cage. Still it is not an uncon- 

 trollable instinct like that of most birds ; nor blind, 

 like that of rats and squirrels at times. I have found 

 beaver houses on lake shores where no dam was 



