INSECT SOCIETIES 



feeding on abundant widely available substances for which 

 competition is not very keen, since special modifications are 

 needed if they are to be utilised economically. Only the most 

 advanced families cultivate fungi, and the value of this crop 

 as food is uncertain. Most termites, however, can and do 

 lay up food-reserves. 



Apart from man, it is the ants which have developed the 

 most varied and also probably the best solutions of this 

 problem. While the more primitive types still live almost 

 entirely by hunting other insects, the others have exploited 

 a gradually widening range of foods. This has been associated 

 with a great increase in the size of the colony. The greater 

 availability of food may, however, be only a part of the 

 reason for this. 



The exact relations between ants and their green-fly cattle 

 are in doubt, but it is certain that they have much less control 

 of their beasts than we have of ours. Cattle by themselves, 

 without an agricultural industry which provides feeding- 

 sturTs, do not much increase the yield per acre. 



This is a point which it would be interesting to study 

 in such species as the British yellow mound-making ant, 

 Lasius flavus, which is almost completely dependent on root- 

 aphides. The cattle are suppliers of sugar and proteins, so 

 that the ants have access to the riches of the plant kingdom 

 without needing the special digestive arrangements of the 

 termites. 



Many ants also feed on plant seeds, and the harvesting 

 ants do so extensively ; but here again no great yield per 

 acre is possible without a proper agricultural system. This 

 has been developed only in the leaf-cutter ants with their 

 fungus gardens, which they providently manure with their 

 own excreta. It is probably not a coincidence that some of 

 these ants make the largest nests with the most numerous 



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