ANIMA-t LIFE OF THE BRITISH ISLES. 



at Jhe Rat will not eat. Therefore, there is 

 no possibility of starving him out. Rat-killing campaigns that 

 do not cover every square yard of the country can only have 

 the effect of temporarily mitigating the nuisance ; for the Rats' 

 fertility is so great and so rapid that the loss of nine-tenths of 

 a generation is quickly made good. A continental statistician 

 has worked out the theoretical progeny of a single pair 

 of Rats after ten years as reaching the appalling figure of 

 48,319,698,843,030,344,720 ! Of course, there is no great value 

 in such a calculation, for it proceeds upon the assumption that 

 every individual lives to become a parent, whereas in fact the 

 mortality in all creatures of such fecundity is enormous, and 

 there are few if any more survivors this year than there were 

 last year. In other words, the great fertility of a race only 

 suffices to make up the wastage from enemy attacks. But the 

 figures serve to show what might happen if the natural control 

 by Weasels, Stoats, Hawks, and Owls were suspended for a 

 short time. But Rats are disseminators of bubonic plague with 

 the aid of their special species of flea. 



Water Vole (Arvlcola amphibius, Linn.). 



In certain directions it appears that failure is the lot of those 

 who have spent the greater part of their lives in trying to 

 spread enlightened views as to the true nature of our native 

 animals and plants. Among a number of such failures two or 

 three may be briefly cited here : you cannot persuade a 

 countryman that a slow-worm is not a snake, that all snakes 

 are not poisonous and to be killed at sight, and that the 

 comparatively inoffensive rodent now to be described is not a 

 rat and of rat-like nature. The name of Water Rat is general 

 as a true folk-name. 



The Voles are of heavier build than the Rats, the head is 

 shorter, thicker, and the muzzle rounded instead of being 



