The lava completely buries the pre-existent land forms over most of its extent.
The reproduction of tsetse-flies is highly remarkable; instead of laying eggs or being ovovivi parous the females deposit at intervals of about a fortnight or three weeks a single full-grown larva, which forthwith buries itself in the ground to a depth of several centi metres, and assumes the pupal state.
The living animal buries itself in the sand with only the posterior extremity projecting into the Siphonopodiidae.
A diggingwasp hunts for insect prey and buries it with the egg, while a true wasp feeds her brood with captured insects, as a bird her fledglings.
Among the more interesting birds may be mentioned the " mound builder " (Megapodius cumingi, Dillwyn), which buries its large eggs in the soft sand along the sea beach, or under great mounds of earth and dead leaves, often at a depth of three or more feet below the surface.