338 PEEFECT SOCIETIES OF INSECTS. 



When the population exceeds the produce of a country, or its inhabitants 

 suffer oppression, or are not comfortable in it, emigrations frequently take 

 place, and colonies 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 cupidity to take possession of what 

 appears to them a more desirable residence. These motives operate 

 strongly on some insects of the social tribes. Bees and ants are particu- 

 larly 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, unless we may distinguish by that name the de- 

 parture 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 ; annoy- 

 ance 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 inducements to them to change their residence. That this is 

 the case might be inferred from the circumstance noticed by Gould l t which 

 I have also partly witnessed myself, that they sometimes transport their 

 young brood to a considerable 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 enlivened by some traits so singular, 

 that I am impatient to relate them to you. They concern chiefly the great 

 hill-ant (F. rufa), though several other species occasionally emigrate. 



Some of the neuters having found a spot which they judge convenient 

 for a new habitation, apparently without consulting the rest of the society, 

 determine upon an emigration, and thus they compass their intention : 

 The first step is to raise recruits : with this view they eagerly accost 

 several fellow citizens of their own order, caress them with their antennae, 

 lead them by their mandibles, and evidently appear to propose the journey 

 to them. If they seem disposed to accompany them, the recruiting officer, 

 for so he may be called, prepares to carry off his recruit, who, suspending 

 himself upon his mandibles, hangs coiled up spirally under his neck; all 

 this passes in an amicable manner after mutual salutations. Sometimes, 

 however, the recruiter takes the other by surprise, and drags him from the 

 ant-hill without giving him time to consider or resist. When arrived at 

 the proposed habitation, the suspended ant uncoils itself, and, quitting its 

 conductor, becomes a recruiter in its turn. The pair return to the old 

 nest, and each carries off a fresh recruit, which being arrived at the spot 

 joins in the undertaking : thus the number of recruiters keeps pro- 

 gressively increasing, till the path between the new and the old city is full 

 of goers and comers, each of the former laden with a recruit. What a 



whole contents of the nest (of course to the very bottom) into a bag, of the contents 

 of which he spreads successive portions upon a cloth so as to allow the ants to 

 escape, and afterwards examines what remains at his leisure. M. Markel has re- 

 cently published a memoir on the coleopterous insects found in ants' nests in Saxon 

 Switzerland, amounting to nearly fifty species. (Germar's Zeitschrift, iii. 203.) 

 1 Gould, 42. 



