400 WILD ANIMALS 
brown rat is said to be a native of India and to have extended 
its range in comparatively recent times, arriving in Europe 
about 1750, and in America about the time of the Revolu- 
tion. It does not seem to thrive in an arid climate and is as 
yet very scarce west of central Dakota. In most sections 
of the world it multiplies with great rapidity, producing from 
six to twelve young ones to each litter and three or four 
litters a year. It is the most injurious pest in the whole 
mouse and rat family and probably the worst in all animal 
Muskrat 
life, destroying millions of dollars worth of property in the 
United States every year. It is also a menace to our health. 
In case of some contagious diseases its body becomes in- 
fested with the germs and then it serves as a means of spread- . 
ing them to all parts of the community. 
Needless to say, rats should be kept off our premises, and 
people living in a town or city should codperate and endeavor 
to exterminate them. They may be destroyed by poison, 
the best substance for the purpose being barium carbonate 
mixed with oatmeal. Their numbers may also be greatly 
