The lid is a movable door which is quickly shut by the inmate's mere withdrawal into his house and as easily opened when the hermit goes forth.

With this system of closing, the abode becomes inviolable; and the Drilus knows it.
Fixed to the surface of the shell by an adhesive apparatus whereof the Lampyris will presently show us the equivalent, he remains on the look-out, waiting, if necessary, for whole days at a time.

At last the need of air and food obliges the besieged non-combatant to show himself: at least, the door is set slightly ajar.

That is enough.

The Drilus is on the spot and strikes his blow.