92 PERFECT SOCIETIES OF INSECTS. 
fortable in it, emigrations frequently take place, and co- 
lonies issue forth to settle in other parts of the globe ; and 
sometimes whole nations leave their own country, either 
driven to this step by their enemies, or excited by cupi- 
dity to take possession of what appears to them a more de- 
sirable residence. These motives operate strongly on 
some insects of the social tribes.—Bees and ants are par- 
ticularly influenced by them. | The former, confined in a 
narrow hive, when their society becomes too numerous to 
be contained conveniently in it, must necessarily send forth 
the redundant part of their population to seek for new 
quarters ; and the latter—though they usually can enlarge 
their dwelling to any dimensions which their numbers 
may require, and therefore do not send forth colonies, un- 
less we may distinguish by that name the departure of the 
males and females from the nest—are often disgusted 
with their present habitation, and seek to establish 
themselves in a new one :—either the near neighbourhood 
of enemies of their own species ; annoyance from frequent 
attacks of man or other animals; their exposure to cold 
or wet from the removal of some species of shelter; or 
the discovery of a station better circumstanced or more 
abundant in aphides ;—all these may operate as induce- 
ments to them to change their residence. That this is 
the case might be inferred from the circumstance noticed 
by Gould*, which I have also partly witnessed myself, 
that they sometimes transport their young brood to a con- 
siderable distance from their home. But M. Huber, by 
his interesting observations, has placed this fact beyond 
all controversy ; and his history of their emigrations is. en- 
livened by some traits so singular, that I am impatient to 
* Gould, 42. 
