Voracious wood-eaters, they will attack fallen logs or growing trees, which they will entirely consume till only the hollow bark remains. This is one great reason why the wood of the teak-tree is so highly valued, as it is the only timber these ants will not touch, and consequently is the one of which all the more important buildings and dwellings are constructed.
This quilted lining, of which the Cerambyx of the Oak showed us the first example, is, it seems to me, pretty often employed by the wood-eaters, Buprestes as well as Longicorns. After these migrants, which travel from the centre of the tree to the surface, we will mention some others which from the surface plunge into the interior.
In some strata three-fourths of the insects are beetles, and as we find that many of them are wood-eaters, we are not surprised. The ants are all winged. Apparently there is as yet none of the remarkable division of labour which we find in the ants to-day, and we may trust that some later period of change may throw light on its origin.