Most species do what the southern wood ants of Europe’s
forests do: they set up house on dry land. In the tropics, they
often live inside small pieces of decomposing wood; and in cooler
climates, they protect the colony by building nests.
There are some for whom the open air is almost a foreign
element, whose whole existence more or less is spent under the
ground. The tiny Plagiolepis pygamea of the south of France
actually owe their survival to this circumstance: in the early
twentieth century, because they were nowhere to be seen, they
were able to avoid extermination by the invading Argentine ants
which killed off all the other insects that they encountered. There
are other species, such as some whose habitat is the tropical
forests, which never come down from the treetops, building their
nests in the canopy and making their living from it.
In eating habits, too, ants have had to adapt to the local diets
on offer. Depending on where they live, they will eat anything
and everything. Some, like wood ants, are omnivorous, and will
consume indiscriminately whatever meets their mandibles.
Others are more particular in matters of diet, such as the carni-
vores, which include the army ants of Africa and Latin America,
well known for their aggressiveness and ready to eat anything
that moves, such as insects, earthworms, and even small mam-
mals which happen to get trapped under branches, where they
are killed, dismembered, and devoured. Or there are those
which, like the southern wood ants, are fond of honeydew,
which is made of vegetable sap ingested then excreted by aphids.
Harvester ants eat seeds collected in the fields. Ants of the genera
Acromyrmex and Atta, among the most abundant in tropical
America, go one better than that, by actually growing their
own fungus, their staple diet, in humus or on fresh leaves,
which they then cut off.
This review of the diversity of eating habits would be incom-
plete without a mention of cannibalism. There are numerous
species in which the adults and the larvae eat eggs laid by the
ON TASTES AND COLOURS
15