Nest-building in ants Formica exsecta (Hymenoptera,Formicidae)

Representatives of the subgenus Coptoformica build composite aboveground nests in much the same manner as red wood ants do. However, despite the superficial similarity, Coptoformica nests show a number of substantial differences that impact on the way in which ants use the nest. The aboveground part of a Formica (Coptoformica) exsecta nest consists of the temporary layer, the outer crust layer, the mound, and the intermediate layer. The material of all the layers includes soil and fragments of plants (picked up or excised), the relative proportion of the two components differing among the layers. The thick, soil-rich crust layer acts as armature and allows a variety of anthill shapes. The intermediate layer and the upper part of the mound harbor quite a few large chambers. Building material is often transferred from nest to nest. On the whole, F. exsecta nests are plastic and movable, which facilitates the activity of these ants in ecotone biotopes.