16 



HOUSE FLY 



Like house flies, most other insects pass through the four 

 forms of egg, larva, pupa, and winged insect. 



In winter nearly all flies die, but a few crawl away behind 

 chimneys and other sheltered places and there live until warm 

 weather comes again. On sunny windows in the attic and 

 barn you may often see house flies on the first warm days of 

 spring. They, and others that have lived through the winter, 

 will be the parents of the summer swarms of flies. 



Other Kinds of Flies. Around stables and on horses and 

 cows you may often see blood-sucking flies that look like house 



flies. Notice that 

 the stable fly has a 

 sharp bill which it 

 carries pointing for- 

 ward from the under 

 side of its head. 

 When eating, the fly 

 thrusts the bill into 

 an animal's skin like 

 a needle and sucks 

 blood through it. 

 In stormy weather 

 the stable flies come 

 into houses, and then 

 people often mis- 

 take them for house 

 flies. 



On decaying meat you may often see black or blue flies 

 somewhat larger than house flies. These flies are called blue- 

 bottle flies or blowflies. The flyblows which you may have seen 

 on old meat are clusters of their yellowish eggs which hatch 

 out larvas as house flies' eggs do. 



There are many other kinds of flies. What kinds that come 

 into our houses do you know ? What kinds can you find about 

 horses and cattle ? 



STABLE FLY (Magnified) 



