Thus we see the plundered Sphex go into her house, pay a leisurely visit to the empty chamber, and the next moment behave as if she had not perceived the absence of the big prey which a little while before had encumbered the cell. Did she not realise the absence of food and egg? Was she really so dull—she, so clear-sighted when playing the murderer—that the cell was empty? I dare not accuse her of such stupidity. She did perceive it. But why then that other piece of stupidity which made her close, and very conscientiously too, an empty chamber which she did not mean to store? It was useless—downright absurd—to do this, and yet she worked with as much zeal as if the future of the larva depended on it. The various instinctive actions of insects are then necessarily connected; since one thing has been done, such another must inevitably follow to complete the first, or prepare the way for the next, and the two acts are so necessarily linked that the first must cause the second, even when by some chance this last has become not only superfluous, but sometimes contrary to the creature’s interest. What object could there be in stopping a burrow now useless, since it no longer contained prey and egg, and which will remain useless, since the Sphex will not return to it? One can only explain this irrational proceeding by regarding it as the necessary consequence of preceding actions. In the normal state of things the Sphex hunts her prey, lays an egg, and closes the hole. The prey has been caught, the egg laid, and now comes the closing of the burrow, and the insect closes it without reflecting at all, or guessing the fruitlessness of her labour.