Fig. 6. House Rat (Rutins norvegicus) . From a si)ecimen taken at. Ft. 

 Collins, Ai)ril 6th. Original. M. A. Palmer, Delineator. 



House-rats eat grain of all kinds, both in the fields and in 

 storage, also small fruits and vegetables, flowering- bulbs, butter, 

 cheese, poultry and birds, contaminate milk and cream, rob hens' 

 and birds' nests; they gnaw through building material and zinc 

 drain pipes, and destroy mattresses, upholstery and shoes, and have 

 been known to steal jewelry and set fire to buildings by gnawing 

 matclies. They also disseminate disease germs that are fatal to 

 man. 



Genus Mus (Mice) 



Like the former genus, house-mice have been introduced into 

 the New from tlie Old World, and are now found in all the settled 

 portions of the country. House-mice are too well known to need 

 description. 



House-Mouse, Mus musculus. 



In Colorado the house-mouse is found in all the settled por- 

 tions of the State. They are frequently caught in traps set for 

 field mice far from settlements. I have seen it on top of the world, 

 at C'orona, Boulder County, altitude 11,660 feet. 



FAMILY GEOMYIDAE (POCKET-GOPHERS) 



This is the pocket-gopher family, and nine different genera 

 are found in North America, only three of which are found in 

 Colorado. 



Members of this family of rodents practically spend their 

 life cycle beneath the ground, seldom coming above the surface. 



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