382 ZOOLOGY 
rotten tree, or are built up of clay. The ants live upon both 
animal and vegetable substances, and are very fond of sweet 
things. Some of them keep Aphides, and by gently stroking them 
with their antennae they induce them to secrete some of their 
honey-dew, which the ants greedily lick up. Certain species 
of beetles are also always found living with ants, though the 
relationship between them and their hosts is not understood. 
Certain species, as Polyerqus rufescens, and in some countries 
Formica sanguinea, make slaves of other and smaller species. 
The slaves are carried off either as ova or pupae, and are reared 
by the masters, who become so dependent upon their slaves 
that if these be removed the colonies of P. rwfescens perish. 
The leaf-cutting ant Oecodoma cuts small circular pieces 
out of leaves, which are carried home often by another indi- 
Fria. 215.—Leat-cutting and foraging ants. 
1. Ocecodoma cephalus. 2. Eciton drepanophora. 3. Eciton erratica. 
vidual, and it is believed that a fungus is grown upon these 
leaves, which the ants eat. The nests of this genus are very 
large, and are built of clay. The leaf-cutting ant does very 
considerable damage to vegetation, and it is difficult to keep 
them away from any spot. They have been known to tunnel 
under a river to reach a wood. 
Group 2. VESPIARIAE (Wasps). 
} i 
Wasps have slender, almost naked bodies, of a usually 
yellow and black colour; the antennae are usually elbowed ; 
the wings are long and narrow, and longitudinally folded when 
the insect is at rest. 
There are three families: the VESPIDAE, or social wasps, and 
two families of solitary wasps—the EUMENIDAE and MASARIDAE. 
Family VESPIDAE.—Social wasps, whose colonies contain 
