9 



INSECT SOCIETIES 



Insects, including even the most successful social species, 

 are so unlike man that their resemblances to one another 

 seem much more important than the differences. We feel, I 

 think rightly, that even the solitary cat is more like us than 

 the most socially-minded ant or the most docile termite. 



Although the problems which have to be solved by any 

 animal which becomes social have always something in 

 common, the possible solutions depend mainly on the 

 structure and behaviour which the species has previously 

 acquired in the course of its evolution. The principal diffi- 

 culties which have to be mastered are, first, how to control 

 reproduction ; second, how to obtain enough food from a 

 limited territory ; third, how to substitute co-operative and 

 docile for solitary, aggressive behaviour ; and fourth, how 

 to adjust behaviour to the varying current needs of the 

 community. The solutions of these four problems by the 

 various types of social insect may be compared with what 

 we find in man and to a less extent in other vertebrates. The 

 problems are not, of course, independent of one another, 

 though it is convenient to consider them separately. For 

 instance, if the food supply were unlimited, control of 

 reproduction would be less important. 



Explanation of biological observations can often be made 

 at several levels. Consider the fact that ants often eat a 

 proportion of the eggs which they lay. The immediate cause 



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