42 



Rats and Mice 



no doubt that they help in perpetuating trichinosis among swine. 

 Mice, when present in such numbers as in the AustraUan plague 

 just discussed, with their parasites and diseases, must constitute 

 a grave danger. Quite apart from the risk of disease being 

 conveyed by the living mice, there is a serious peril of water 

 becoming contaminated by their putrefying bodies. The use of 

 grain fouled by them, for human food or even for that of domestic 

 animals, is an extremely risky proceeding — unless, indeed, really 

 efficient means of cleansing and sterilizing it can be devised. 



Control of the Mouse Population. — Should we succeed in 

 exterminating or greatly reducing the rat population of this 

 country, we shall in all probability disturb the balance of Nature 

 still further in favour of the House Mouse and our other small 

 Muridae. The presence and competition of rats greatly diminish 

 both the food-supply and the space available for mice ; remove the 

 rats, and there will be nothing to hinder the steady natural increase 

 in the numbers of mice until the latter have filled up the vacancy 

 left by the rats. If, therefore, we fail to adopt appropriate 

 measures against mice at an early stage in our campaign against 

 rats, we shall find ourselves confronted, in due and rapid course, 

 with a mouse plague. 



The steps to be taken against mice are similar to those re- 

 commended against rats. The chief of them are the following : — ■ 



1. Protection of food supplies. 



All food, whether of man or beast, should be kept, as far as 

 possible, in mouse-proof receptacles. 



Unprotected accumulations of edible refuse should never be 

 permitted. 



2. Diminution of the available shelter for mice. 



Eubbish heaps of all sorts should be abolished. 



Effective rat-proofing of buildings will render them mouse- 

 proof to a considerable degree. 



Mouse-holes should be stopped wherever possible ; for this 

 purpose many expedients, such as filling with cement and broken 

 glass, or running with gas-tar, are available. 



3. Destruction of mice. 



Indoors and about houses this is best accomplished by means 



