The dung-beetle works from without inwards; she begins to dig at the mouth of the burrow, and afterwards re-ascends and accumulates the excavated material on the surface.

The larva of the Cigale, on the contrary, works outward from within, upward from below; it opens the door of exit at the last moment, so that it is not free for the discharge of excavated material until the work is done.

The first enters and raises a little rubbish-heap at the threshold of her burrow; the second emerges, and cannot, while working, pile up its rubbish on a threshold which as yet has no existence.
The burrow of the Cigale descends about fifteen inches.

It is cylindrical, slightly twisted, according to the exigencies of the soil, and always approaches the vertical, or the direction of the shortest passage.

It is perfectly free along its entire length.