CHAPTER V. 



THEIR RELATION TO THE ANIMALS THAT 

 FEED ON THEM 



THIS subject might be dismissed with a very few 

 words in the statement that a large number of birds sub- 

 sists entirely on insect food, another large number feeds 

 on insects during certain seasons or takes them indiffer- 

 ently as part of the general diet, and that the same is 

 true of certain mammals, reptiles, batrachians and the 

 like. Active defence very few insects are able to make 

 against any of these enemies, and we may say broadly 

 that the number of insects that may be destroyed by ver- 

 tebrate enemies is limited only by their appetite and 

 their ability to find prey. The only practical defences 

 that an insect has, are its ability to escape the notice of 

 its pursuer and its enormous fecundity ; points that have 

 been elucidated to some extent in a previous chapter. 



So we can say, roughly, that all kinds of insects 

 serve as food for some kind of animal. That is not 

 strictly true, of course, for there are some that are so 

 minute that they are taken only by accident and a few 

 others that seem to be so offensive that no animal will 

 touch them; but as a general statement it is accurate 

 enough. Some birds and animals eat indifferently 

 any thing that comes along; others have a very limited 

 diet and go outside of their normal range only under 

 the pressure of necessity, which is usually spelled 

 hunger. Some animals eat what others avoid, e.g., 

 hairy caterpillars, and some insects feed so as to be out 

 of reach of all save animals especially adapted to find 

 them, e.g., borers sought by woodpeckers. 



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