as Enemies of Mankind. 



^3 



This last case is especially instructive because the extent of 

 the means of destruction employed, as well as that of the area of 

 operations, has remained constant during the three years covered. 



If now we may take the number of rats killed as an index of 

 the number of rats living, then we may conclude from such 

 returns that the measures adopted for the destruction of rats up 

 to and including the year 1915 have not resulted in bringing about 

 any absolute decline in the rat population ; in fact, the figures 

 suggest that destruction has not even been able to keep pace with 

 the natural increase of that population. 



Now, although the war has rightly not been allowed to interfere 

 with the catching of rats in our chief ports, because of the 

 paramount importance of protecting the public health, it has most 

 seriously interrupted and discouraged such work in ordinary 

 towns and in the rural districts. Military service, the manufacture 

 of -munitions, and the great rise in wages in the towns have all 

 contributed to denude the country and the towns of that labour 

 which was formerly devoted to rat extermination. The need for 

 enforcing economy in the use of foodstuffs has given rise to a 

 series of regulations, which in effect prohibit the use of all food for 

 bait, and for conveying poison or virus to rats. Such regulations 

 also have therefore played a great part in obstructing or stopping 

 the indispensable work of the rat-catcher. The result is deplorable. 

 From all parts of the country come complaints of a great increase 

 in the numbers of rats present, and of the great damage they are 

 doing to ordinary agriculture as well as to the produce of the 

 allotment holder. Such a result was bound to ensue, even if 

 nothing had been done to assist the rats beyond the temporary 

 cessation of our efforts to destroy them. But the great national 

 endeavour to increase the internal sources of food has benefited 

 rats as well as citizens. The numbers of rats, no less than the 

 numbers of men, depend entirely upon the food supply ; and as 

 all classes have become or are becoming producers of food, so in 

 proportion the capability of the country to support rats has grown 

 and will grow. Every new allotment, new chicken -run or rabbit 

 hutch, offers a new niche in Nature for the accommodation and 

 maintenance of the rat. As is shown in the following paragraphs, 

 the rats not only are able to, but must take advantage of these 

 new outlets for their numbers, for with them it is a case of colonize 

 or perish. For our safety it is imperative to find a means of 

 controlling the rat population. 



c 



