82 PRACTICAL ZOOLOGY 



cent state. Like the woodchucks, certain bears, frogs, etc., they 



hibernate during the cold, unfavorable months. 



Prevention of Breeding. — The best means of decreasing the 



number of house flies is undoubtedly to prevent them from breed- 

 ing. This means that the materials in 

 which flies lay their eggs and develop 

 should be protected from them in 

 some way- Horse manure is the 

 principal breeding material. Either 

 fly-proof receptacles or chambers 

 should be provided for manure, or 

 the manure, when accessible to flies, 



^iiiii 



Fig. 52. — Enemies of the house fly. 



A, centipede ; B, dead fly surrounded by spores from a fungous plant which has 



killed it. (After Folsom.) 



should be treated with some substance which kills the maggots. 

 A small amount of chloride of lime thrown over the manure 

 will do this, or an application of iron sulphate solution, in 

 the proportion two pounds of iron sulphate to one gallon of 



