Ants live in dwellings of the most varied kind, many being underground.
In a large number of species ant-hills are constructed of various loose
materials, our common native wood-ant (_Formica rufa_) being a good
example of this. An Asiatic ant (_Oecophylla_) constructs a summer-house
of leaves in a curious fashion. The larva possesses silk-glands from
which a sticky fluid exudes, hardening quickly on exposure to the air.
Advantage of this is taken by the workers, for they hold larvæ in their
jaws, and employ them as living gum-bottles, while the leaf-edges to be
cemented are held in position by other workers.
Some South American ants construct hanging nests in trees, by which
protection against floods is secured. Other ants in the same part of the
world make curious homes which well deserve the name of “hanging
gardens,” for they are mainly constructed of living plants, some of
which have never been found in any other situation. The plants are
cultivated and tended by the ants with which they are associated. The
soldiers of certain ants (_Colobopsis_), which tunnel out homes in the
wood of trees, play the part of living front doors. Every entrance to
the nest is guarded by one of these hall-porters, its huge head not only
exactly filling the aperture, but closely resembling the adjacent bark
in appearance. If this curious door be touched by a bit of stick or a
feather, it remains shut, but is immediately opened when stroked by the
antennæ of a worker.