as Enemies of Mankind. 



41 



great hordes of Field Mice and outdoor-living House Mice arc 

 developed simultaneously. Such a plague brings ruin and devas- 

 tation to the countryside ; the ground is riddled with holes, the 

 crops and many young trees utterly destroj^ed. The plague may 

 run a course of several months, but sooner or later disease 

 breaks out among the rodents, they succumb in millions, and in a 

 short time their numbers are once more normal, or sub-normal, 

 and the plague is at an end. 



Kecently South Australia and Victoria have been visited by a 

 very severe ''mouse plague," the worst ever experienced in 

 Australia. The principal species involved was the House Mouse, 

 but it was assisted not only by various native species but by 

 battalions of rats as well. The plague developed in the bush as 

 well as in the wheatland in 1916 and 1917, after two abnormally 

 heavy harvests. The wheat grown was sold to the British 

 Government, and the grain was stacked in bags ready for ship- 

 ment. Shipping was cut off and the stacks remained unprotected 

 from a possible attack by the rodents. As cold weather approached 

 the mice invaded the stacks ; an eye-witness of the result says : — 

 " The wheat stacks instead of being as orderly as a brick wall are 

 now evil-smelling heaps of wheat, mice alive, mice dead, and 

 rotten bags." The damage done to the wheat is estimated to be 

 well over £1,000,000; what is worse, much of that which has 

 been re-bagged is in an indescribably filthy condition. The mice 

 were in billions. One farmer put down poisoned meat in his house, 

 and next morning he picked up 28,000 dead on his verandah, and 

 he added that he only stopped then '' because he was tired." At 

 one wheat-yard 70,000 were killed in an afternoon ; these must 

 have weighed about one ton. Myriads died from a disease, in 

 appearance somewhat resembling ulcerative syphilis ; and the 

 men trying to cleanse the stacks contracted a kind of ringworm. 

 Large quantities of hay were also ruined, and horses fed upon the 

 dirty residue were killed. Of course, much other property was 

 injured ; thus, in a grocer's shop at Port Lorne, South Australia, 

 many packages of lead pencils were devoured — the flavour of the 

 wood appealing to the mice ; and they ate the leaden bullets out 

 of some hundreds of cartridges. Here also the seaweed on the 

 beach was swarming with mice. 



As regards their general relation to the public health, many of 

 the remarks made above as to rats will apply to mice equally 

 well. In certain circumstances they convey plague, and there is 



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