ENTOMOLOGY 343 



nary care and cleanliness will preserve an adult from all these 

 pests or will enable the prompt recognition of the infestation. 

 Children have to be watched, as they are not always choice in the 

 selection of their playmates, and in public schools are often brought 

 into close contact with others who are not so well looked after. In 

 a general way, be clean and careful to prevent infection ; if infection 

 occurs be prompt to act, and use a greasy material to come into con- 

 tact with the parasites. 



Flies. A number of species of flies occur in houses, but most 

 of them do not breed there. The largest percentage consists of the 

 common house or typhoid fly, and this is a nuisance in every 

 sense of the term. It is not only an annoyance, but is actually dan- 

 gerous as a carrier of any sort of germ disease. The adult gets into 

 everything, walks over everything and feeds on or at least tastes 

 almost everything. Germs may be taken up on the hairy pads of the 

 feet from excrementitious matter, expectorations or other waste, 

 and may be carried to food or directly to the individual. From a 

 sick room, flies should be most rigidly excluded. 



House flies lay their eggs on and their larvae live in excre- 

 mentitious material of many sorts; but the favorite food is horse 

 dung, and in a small quantity of this a great number may de- 

 velop. Sometimes they are found in garbage pails or barrels; but 

 these are more usually used by other species. The larvae of flies 

 are maggots, and it takes only a little over a week for them to pass 

 through all the stages, from egg to adult. Development, there- 

 fore, takes place outdoors as a rule, and only the adults come into 

 the house. They hibernate there if given a chance, and in a well 

 warmed residence flies are never entirely dormant. 



Another common species is somewhat larger than the house 

 fly, metallic green or blue in color, and this is attracted to and breeds 

 in garbage and animal and vegetable refuse of all kinds. If a gar- 

 bage pail is left uncovered or loosely covered in summer for three or 

 four days, it will be found swarming with the maggots of this species, 

 ranging in size from those just out of the egg to half grown or 

 more. These flies are not so obtrusive indoors and do not so usually 

 bother the person or get into cooked food. 



Larger yet, and comparatively more rare, is the blue-bottle, or 

 Wow fly; a dull blue, stout, bristly species which makes a loud 

 buzzing noise and is more annoying from that cause than from 

 almost any other. The larvae or maggots of this species develop 

 chiefly in decaying animal matter. A dead mouse will support a 

 dozen ; a dead rat will mature a large brood. All these flies are actu- 

 ally scavengers, hence they have a real function and the best way to 

 deal with them is to remove the cause for their existence. Allow no 

 decaying matter in or close to the house, and keep all garbage re- 

 ceptacles so tightly covered that the flies cannot get at the contents 

 to lay eggs. 



Flies do not like the dark, and will fly out of a small lighted 

 opening, if the remainder of the room be darkened. They are 

 attracted by food odors, hence are most numerous in kitchens and 



