HUMAN AND OTHER SOCIETIES 123 
separation appears to be difficult or to require 
some time. 
Observations show that unpalatable insects especially 
have this habit, but too few have been made to justify 
a definite statement. If this prove to be a fact, its 
meaning is clear—they do not require this method for 
the escape of either male or female, because they are not 
so liable to attack. 
In this connection some observations, which 
have been made when birds are given copu- 
lating insects as food, have a bearing—one of 
the two copulating individuals is seized, but 
instead of both being at once swallowed, the 
bird for some reason almost always shakes or 
scrapes off the other. The impression gained 
is that the bird mistakes the second insect 
for an adherent foreign body. 
It appears, therefore, that were the male 
of a copulating pair to be seized by a pre- 
datory animal, there would be considerable 
chance of the female escaping. 
The following are methods of self-advertise- 
ment whereby male insects draw the attack 
of enemies : 
1. Position.—Males rest on the top of the 
female and are therefore more likely to be 
seized. In many cases the males are very 
much larger than the females and completely 
