USEFUL HYMENOITERA. 191 



narrower than the head, which is nearly as large as the 

 abdomen ; they are wingless. 



The lan-ac are thickest, somewhat curved, white, and apodal. 

 Thejmpae are soft and white, with the limbs separately invested, 

 usually enveloped in thick white cocoons, M'hen they are known 

 as ants' t'iigs. 



The ants fly in July and August in still warm weather, 

 often in cloud-like swarms. The ? , which loses her wings after 

 pairing, either lays her eggs the following spring in the old 

 nest, or she forms a new colony in the ground or in a hollow 

 tree. The larvae live in thousands in the ant-hills, and are 

 fed and carried about by the numerous i? , of which there may 

 be 5,000 and more in one ant-heap. In case the ant-hill 

 should be disturbed, the ': endeavour to carry the pupae to a 

 place of safety. 



The perfect insects come out at the end of May, or the 

 beginning of June, after the i? have opened the cocoons. First 

 appear the ? , then the S , and last the ^ . The J die soon 

 after copulation ; as the cold increases many of the 2 also 

 die ; the '? live over the winter. Ants are endowed with a 

 remarkable sense of locality; if their nest be injured, they 

 eject formic acid, which slightly burns the skin. 



For a long time past the usefulness of these little animals 

 has been recognised. They attack and kill numerous insects 

 and larvae, especially small caterpillars, and clean the forest 

 of many dead insects. In utilising other insects they show 

 extraordinary ability for creatures so low in the animal 

 khigdom. Some ants, living in hollow trees, carry the larvae 

 of a beetle, Cetonia aurata, L., into their nests, as. these larvae 

 chew up the wood into small pieces for them ; in the same 

 way Claviger foceolatas, Preyssl., lives in the nests of the 

 yellow ants. 



Plant-lice are also kept in ants' nests, as the ants use 

 the honey-dew which exudes from them to feed their young, 

 milking them like cows. 



Trees at the foot of which there are ant-heaps remain 

 uninjured during wide-spread devastation by caterpillars, like 

 oases in the desert, and the fruit-cultivators in the province 

 of Mantua place in the spring of every year a colony of ants 



