The Wonderful Ways of Insects and Spiders [ 233 



What is An Insect? 



People have a habit of referring to every small, creeping animal 

 as an insect. However, many creatures that are so called do not 

 belong to the classification of insects. Spiders are not insects nor 

 are worms and centipedes. How, then, do we really determine 

 what is or isn't an insect? 



An insect in the adult stage has three pairs of legs no more, 

 no less. It also has three distinct parts to its body the head, the 

 thorax, and the abdomen. And all insects have a shell-like covering 

 to protect their bodies. 



How INSECTS ARE ABLE To MOVE 



Insects have no inside bone structure to help them move 

 as our bones help us; but movement is possible for them because 

 each end of their muscles is attached to the hard outer covering 

 that serves as an "outside skeleton." A muscle, for example, which 

 acts to move a leg forward has one end attached to the hard cover- 

 ing of the leg and the other end attached to the covering of the 

 thorax in front of the legs. When this muscle contracts, it pulls 

 the two solid attachments closer together and the leg moves for- 

 ward. 



It might seem impossible for a creature encased in a rigid cov- 

 ering to bend. However, the insect has joints in places where the 

 body wall is flexible. That is why the creature can bend, some- 

 what as a knight of old could bend because his suit of heavy armor 

 was jointed. 



THE LOWLY BUG 



Frequently the term "bug" is mistakenly used for "insect." 

 Though all bugs are insects, in the scientific sense, not all insects 

 are bugs. Bugs belong to a specific group that varies within itself 

 in many respects; but all bugs are alike in having piercing, suck- 

 ing mouth parts. The group includes the giant water bugs (also 

 known as electric-light bugs because the adults often fly about 

 electric lights) , squash bugs and bedbugs. 



