on a hole covered
with trunks of trees, at the bottom of which he may kill the beast
without danger. Certain insects practise this method of hunting. The
Fox, for instance, so skilful a hunter in many respects, constructs an
ambush when hunting hares.[11]

[11] C. St. John, _Wild Sports, etc._, chap. xx.

The larva of the Tiger Beetle (_Cicindela campestris_) constructs a
hole about the size of a feather quill, disposed vertically, and of a
depth, enormous for its size, of forty centimetres. It maintains
itself in this tube by arching its supple body along the walls at a
height sufficient for the top of its head to be level with the surface
of the soil, and to close the opening of the hole. (Fig. 1.) A little
insect--an ant, a young beetle, or something similar--passes. As soon
as it begins to walk on the head of the larva, the latter letting go
its hold of the wall allows itself to fall to the bottom of the trap,
dragging its victim with it. In this narrow prison it is easily able
to obtain the mastery over its prey, and to suck out the liquid
parts.[12]

[12] Lamarck, _Histoire des Animaux sans Vertebres_, 2e
edition, 1835, p. 676.

[Illustration: FIG. 1.]

The _Staphilinus Caesareus_ acts with still greater shrewdness; not
only is his pit more perfect, but he takes care to remove all traces
of preceding repasts which might render the place obviously one of
carnage. He chooses a stone, beneath which he hollows a
cylindro-conical hole with extremely smooth walls. This hole is not to
serve as a trap, that is to say that the proprietor has no intention
of causing any pedestrian to roll to the bottom. It is simply a place
of concealment in which he awaits the propitious moment. No creature
is more patient than this insect, and no delay discourages him. As
soon as some small animal approaches his hiding-place he throws
himself on it impetuously, kills it, and devours it. Near his ditch he
has hollowed a second of a much coarser character, the walls of which
have not been smoothed with the same care. One here sees elytra and
claws piled up; they are the hard and horny parts which he has not
been able to eat. The heap in this ditch is not then an alimentary
store. It is the _oubliette_ in which the _Staphilinus_ buries the
remains of his victims. If he allowed them to accumulate around his
hole all pedestrians would come to fear this spot and to avoid it. It
would be like the dwelling of a Polypus, which