172 CATERPILLARS AND THEIR MOTHS 



of day. On such occasions many fall victims to robins, 

 which dance around them as if trying to choose the 

 best spot for a peck, then seize them and carry them 

 off a little way before killing them. 



Several parasitic flies sting the caterpillars, some- 

 times when the larvae are so small that they die, 

 covered with cocoons, before the fourth molt. 



