EARLY in September a little black Tachytes suddenly became very common in the garden. The first one that we saw was going forwards in a series of long jumps, carrying a small grasshopper which was held by the base of the antennæ. She soon doubled on her tracks, and it became evident that she did not know her way; but after going about in circles for two minutes she ran into her nest. When she came out she spent a long time in circling around, flying close to the ground in wavy, snaky lines, occasionally alighting to run a few steps; but in spite of this locality study, ten minutes later, when she came jumping along with her second grasshopper, she had lost her nest again and hunted about just as before, twice going directly over it without seeing it. While she was thus occupied another wasp of the same species attacked her and tried to get possession of the grasshopper, but the rightful owner was able to defend it. At last it was stored away, and she proceeded to fill the nest, scratching the earth in with her first legs and working it down with the tip of the abdomen. She worked quietly but steadily for ten minutes, closing the place neatly, and then brought bits of leaf and pieces of earth to cover it all over. [Illustration: TACHYTES] On the same afternoon we saw another of these wasps digging her nest, but she was so much disturbed when we came anywhere near her that we were obliged to retire. On the next day we saw her astride of a small grasshopper, jumping along like the one of the day before. She too had great trouble in finding her way. When she reached the nest she laid her prey down while she went inside for a moment, and then, coming out, seized it by the antennæ and backed in with it, instead of taking it in forwards as was done in the other case. Another wasp of this species carried a much larger grasshopper, which was so heavy that she could not jump with it, but was obliged to keep to the ground. In this case only one was used instead of two, which is the usual number. This wasp was first seen at a distance of twenty feet from her nest, and yet she went straight to the right spot without the least confusion, showing that some individuals of the species have a better idea of locality than others. The nest is a short, shallow tunnel with an enlargement at the end, within which are placed the grasshoppers, on their backs, with their heads in. Earth is packed solidly into the tunnel, but not into the cavity at the end. We took two eggs of this species. Each was placed across the thorax of the grasshopper at the base of the neck, on the ventral side. Both hatched at the end of thirty–six hours from the time they were laid, ate for three days, and then spun their cocoons. One of them ate only one small grasshopper, leaving a second one untouched, while the other finished the large grasshopper that formed her sole provision.