46 ECONOMIC MAMMALOGY 



here. These rodents attack almost everything that can be eaten by them 

 or used in the construction of their nests, such as clothing, furs, leather 

 goods, cloth, bedding, rugs, carpets, upholstery and textiles of all sorts. 

 They gnaw holes in baseboards, doors and other woodwork of build- 

 ings, boxes and bins, injure books, destroy valuable documents and 

 even paper money, where they are accessible, and commit many other 

 depredations. Their status in relation to the fire hazard in buildings is 

 discussed in another chapter. 



Native rats, squirrels and other rodents also sometimes enter homes 

 and other buildings, especially in country districts, and carry off, in- 

 jure, or destroy various articles. The sins of the "pack rat" of the 

 Rocky Mountains, and "trade rat" of California in this respect, are 

 quite notorious. 1 They will carry off almost anything not too large or 

 heavy for them to move, and a single large nest will sometimes repre- 

 sent the ruin of several suits of clothes, quilts or blankets, besides con- 

 taining jewelry and trinkets of many kinds filched from the human 

 occupants of the premises. 



Porcupines, as has been elsewhere noted, sometimes injure fruit 

 trees, but their usual habitat is in the forests, where they undoubtedly 

 do considerable damage to forest trees. In Alaska, birch trees have 

 been found entirely stripped of their bark and thereby killed by porcu- 

 pines. 2 Fortunately they are seldom plentiful enough to be a serious 

 pest. Mice and other small rodents do more or less damage to forest 

 and shade trees, as also to fruit trees and shrubbery, by gnawing the 

 bark and girdling the roots, trunks and branches. Meadow mice girdled 

 1000 six-year-old pines on one five-acre tract in New York. 3 



Beavers cut down large numbers of trees for food and to use in the 

 construction of their dams and houses, but in most localities they use 

 only trees of small commercial value, such as aspens in the Rocky 

 Mountains and cottonwoods on the plains. They have been known to 

 cut valuable forest trees in some localities, and in a few instances even 

 shade and fruit trees. When they become troublesome it is not difficult 

 to stop their depredations by trapping them. Trees may be protected, 

 if necessary, by surrounding each with a cylinder of woven-wire fence 

 material. They sometimes build their dams in such positions as to flood 

 and thereby damage roads and fields, and destroy forest trees by turning 



1 Parks, Journ. Mammalogy, in, 241-253, 1922. Burnett, Office Colorado State 

 Entom., Circular No. 25, p. 9, 1918. 



2 Murie, The porcupine in Alaska, Journ. Mammalogy, vn, 109-113, 1926. 



3 Silver, Farmers' Bull, No. 1397, 1924. 



