138 NORTH AMERICAN INSECTS. 
These insects are rarely seen by day, being concealed on 
or under fences, or houses, or under the leaves of trees and 
bushes, and you have only to strike upon a bush with your 
walking-stick, or parasol (for I write also for the young 
ladies), when a swarm of these insects will sometimes fly 
out of it, and be easily caught in a net. As soon, however, 
as night sets in, their airy promenades begin, and unless 
snapped away by the cruel whip-poor-will, or a voracious 
bat, or burned alive by the flame of some candle, they con- 
tinue flying about all night. 
It is very singular that nocturnal insects, which conceal 
themselves from the daylight, are so apt to fly toward a 
light in the night. But such is the fact, as almost all can 
testify who have seen them flying around alight in a warm 
summer evening, when the windows are open, until they 
disabled themselves, so that they could not fly. This is an- 
other way of catching these insects; and still another is to 
spread a white sheet over the turf of your garden in a warm 
summer evening, and set a lantern in the midst of it: nu- 
merous swarms of guests of all shapes and colors will im- 
mediately appear upon it. 
Figure 29. 





Caterpillar of the Asterias. 
But if we examine these insects, which are so much at- 
tracted by the light, we find the greatest part of them 
males. Hence the celebrated and ingenious Professor 
Oken thinks that the females of the nocturnal lepidoptera 
