THE SOCIAL INSECTS 



and may then serve to dry the nest or to remove odours. 

 Nests in natural situations will less often be exposed to the 

 sun than when they are kept above ground in nesting-boxes, 

 so that trumpeting seems to be observed much more fre- 

 quently in conditions of semi-domestication. It is behaviour 

 of the same kind as that observed in wasps when their nest 

 gets too hot. 



At the height of its activity the colony is able to store 

 considerable quantities of food, especially in some species 

 and especially those nesting below ground in which 

 workers become very numerous. Such nests may have three 

 or four hundred workers, but one hundred and fifty or less 

 is more common. Nectar, later turning to honey, is stored 

 chiefly in empty cocoons which are not used again for brood 

 rearing as are the cells of a wasp-comb. Since the egg-pockets 

 are built near the top of the sides of the cocoons, the nest 

 grows upwards and the empty or honey-containing cocoons 

 are mainly in the lower part of the nest. Sometimes some 

 waxen honey-pots are also built round the edge of the nest, 

 but according to Plath these are temporary structures. The 

 food stored in them is for daily use and they are often broken 

 down and the wax used elsewhere. Some of the species also 

 store considerable quantities of pollen, either in empty 

 cocoons or in large waxen cylinders which may eventually 

 reach the length of more than two inches. The surface 

 nesting " carder bees " store pollen in little wax pockets at 

 the sides of the groups of grubs ; the quantity stored in this 

 way is quite small. Since the colony does not survive the 

 winter there is no point in making a large store of food as 

 the honey bee does. But, as explained later, the store of honey, 

 at any rate, has a very important function in preparing the 

 young queens for their winter rest. 



The climax of the colony comes when the males and young 



88 



