THE HOUSE-FLY 31 



diseases. They not only annoy the patient, but they are 

 liable to convey contagion to other members of the 

 household. The faces of babies should be screened with 

 mosquito netting. 



Protection of food. — Food and confectionery exposed 

 in public places, lunch counters, and restaurants should 

 be protected from flies by screens, cases, or other con- 

 trivances. One ought to boycott lunch counters that 

 expose their food to the dust, flies, and other insects 

 always found in abundance about railway stations, and 

 restaurants. The exposure of fruits in the ordinary street 

 fruit stands in cities is dangerous to public health. 



The use of screens. — After all is done that seems pos- 

 sible, still there will be some flies, but these may be largely 

 kept out by a thorough screening of all doors and windows, 

 as is fully described in the discussion of the mosquito. 

 Especially will there be flies and filthy, germ-bearing ones, 

 if the neighbors take no pains with their stables and closets. 



Flies enter a house largely through the back door of the 

 kitchen. They are attracted to this opening by the odor 

 of the cooking and by the warm air pouring outward when 

 the door stands open. This is especially noticeable on a 

 wire gauze door toward night if the main door is left ajar. 

 The wire screen is often literally black with flies and 

 whenever it is opened some of them are almost sure to 

 enter. Moreover, this door is opened, probably, more 

 than any other in the house. The only efficient method 

 of keeping flies out of the kitchen is to build a porch 

 (Plate 1) over the back door and screen the three 

 open sides. Of course a wire gauze door must be 

 placed in one side wherever it is most desired. With 

 this arrangement, the flies cannot gather on the screen 



