HYMENOPTERA. 637 



There are many forms of ants* nests, but each species 

 builds the same sort. Sometimes the nest is a simple tun- 

 nel in the earth, sometimes a large mound with tunnels and 

 galleries extending many feet under ground ; and some 

 species Hve in decayed trees. In the tropics a greater variety 

 of these structures occur than in our country. Some 

 colonies own several mounds. One colony of one species 

 has been known to have two hundred mounds, covering 

 several hundred square yards. Ants are also very good 

 road-makers, sometimes making clean, beaten paths, and 

 sometimes working out covered ways under rubbish. 



As to their food, ants are general feeders, eating animal 

 food and also sweet substances, like the juice of fruit and 

 sugar ; and they are also very fond of the honey-dew given 

 off by Aphids; and the ants regard these Aphids as their 

 milch-cows. An ant will walk up to an Aphid and stroke its 

 back with its antennae, and immediately the pleased Aphid 

 gives forth a drop of sweet fluid, which the ant at once 

 drinks up. The ants take very good care of their cattle, 

 and will carry them to new pastures if the old ones dry up. 

 They also carry the Aphid-eggs into their nests, and keep 

 them sheltered during the winter, and then carry the young 

 plant-lice out and put them on plants in the spring. When 

 ants are seen going up and down the trunks of trees it 

 is safe to suppose they are attending Aphids. They also 

 care similarly for some of the Coccids (especially some 

 Lecaniums) and a few other honey-giving insects (Tree- 

 hoppers and others). 



Many species of beetles are also found in ants' nests, but 

 the ants have never revealed to us why these insects are 

 allowed to dwell in peace in their habitations. 



We have many evidences that ants think, but what goes 

 on in their minds we can only guess. They have a language 

 that seems to exist through the sense of touch. The an- 

 tennae are most sensitive organs, and when ants meet they 

 cross their antennae and pat each other. If one finds some 



