70 
ENEMIES OF THE CATERPILLAR. 
lie picks it out and eats it. The woodpecker gets 
a bad character from this habit of his. Many 
people fancy that he is injuring the tree; instead 
of which, he is doing it good service, and freeing 
it from its enemies. 
Then there is thaf'handsome gaily-dressed fly, 
that looks very much like a wasp. You may see 
dozens of them on a hot summer day, flying to 
and fro in search of food, or buzzing in and out 
of little holes in the ground. These holes have 
been made by the industrious flies themselves; and 
here they lay their eggs, and also take the trouble 
to collect a supply of caterpillars, to serve as 
provender for their own little grubs to feed 
upon. 
It is astonishing how hard they will work, led 
on by the instinct to provide for their young. 
You may see one of them scooping her hole out of 
the solid ground, and carrying away heavy loads 
of earth to a distance, lest they should roll back 
again. "When she has finished, she lays her egg 
within the hole, and flies away in search of cater¬ 
pillars. Often, you may see her dragging along 
a green caterpillar, three times as big as herself; 
and she will drag it too, a distance of several 
yards, a long way for such a heavy load. When 
she gets to her hole, she takes away the pellet 
of earth that was placed at the entrance, and 
