52 SOCIAL HABITATIONS. 
In its winged and pupal states the insect is perfectly 
harmless, but in its larval condition it becomes a terrible 
pest. Most caterpillars wage war singly on the foliage, 
and though they do much damage, their ravages are con- 
ducted in a desultory manner. The Small Ermines, 
however, band themselves together in hosts, and march 
like disciplined armies to the attack, invading a district 
SMALL ERMINE MOTH. 
and completely devastating it before they proceed to 
another. 
They live in large tents, placed among the branches of 
some tree, and composed of silken threads, which are 
loosely crossed and recrossed in various directions. From 
this centre the caterpillars issue in vast numbers, each 
individual spinning a strong silken thread as it proceeds, 
which acts as a guide to the nest, just as the fabled clue 
