6 HOUSEHOLD INSECTS 



BREEDING PLACES FOR FLIES 



Without doubt, house-flies prefer piles of horse m 

 whenever these can be found. This has been shown by 

 many observers. Next to horse manure, flies apparently 

 prefer human excrement. At least, open closets in the 

 back streets of cities have been shown to be one of the 

 main sources of house-flies in such localities, especially 

 in those regions in which there are few or no horse stables. 

 Moreover, Howard has shown that the larva? of house- 

 flies are often found in chance droppings of human feces 

 in back allies, yards, and so on. We would emphasize 

 the fact that the most dangerous breeding places for 

 flies are in open closets ; for in these places the germs 

 of typhoid fever, dysentery, and other enteric diseases 

 are present in great abundance. 



House-flies will also breed in cow manure especially 

 when moist enough. Piles of stable manure containing 

 rotting straw or barnyard refuse are favorable breeding 

 places. Manure, bedding, and filth of pig-pens breed 

 large numbers of flies ; even the refuse of poultry houses, 

 if composed in considerable part of rotting bedding, may 

 contain maggots. The decaying and fermenting garbage 

 from kitchens, if allowed to stand long enough in barrels 

 or cans, may become breeding places for flies, although it 

 would seem that the stable fly, Muscina stabulans, is the 

 more common fly in such situations. 



Forbes' assistants bred 267 house-flies from carrion in 

 the streets, which runs contrary to former ideas concern- 

 ing carrion and house-flies. It is probably safe to say 

 that house-flies will breed in almost any vegetable 

 matter that lies long enough to ferment and decay. 



