In tropical countries ants sometimes make their nests in the hollow thorns of trees or on leaves; species with this habit are believed to make a return to the tree for the shelter that it affords by protecting it from the ravages of other insects, including their own leaf-cutting relations.
An interesting species of the last is the leaf-cutting ant (Eciton) which lives in large underground colonies and feeds upon a fungus produced by leaf-cuttings stored in subterranean passages to promote fermentation.
Still more curious is the mimicry of another of these insects from Venezuela which is found in company with a leaf-cutting ant (Oecodoma cephalotes) of that country.
Worker caste polymorphism has a genetic basis in a leaf-cutting ant.
