The Common Wasp has chanced to set up house beside one of the walks in my enclosure, which enables me to experiment with a bell-glass. In the open fields I could not use this appliance, because the boys of the countryside would soon smash it. One night, when all was dark and the Wasps had gone home, I placed the glass over the entrance of the burrow, after first flattening the soil. When the Wasps began work again next morning and found themselves checked in their flight, would they succeed in making a passage under the rim of the glass? Would these sturdy creatures, who were capable of digging a spacious cavern, realise that a very short underground tunnel would set them free? That was the question. The next morning I found the bright sunlight falling on the bell-glass, and the workers ascending in crowds from underground, eager to go in search of provisions. They butted against the transparent wall, tumbled down, picked themselves up again, and whirled round and round in a crazy swarm. Some, weary of dancing, wandered peevishly at random and then re-entered their dwelling. Others took their places as the sun grew hotter. But not one of them, not a single one, scratched with her feet at the base of the glass circle. This means of escape was beyond them. Meanwhile a few Wasps who had spent the night out of doors were coming in from the fields. Round and round the bell-glass they flew; and at last, after much hesitation, one of them decided to dig under the edge. Others followed her example, a passage was easily opened, and the Wasps went in. Then I closed the passage with some earth. The narrow opening, if seen from within, might help the Wasps to escape, and I wished to leave the prisoners the honour of winning their liberty. However poor the Wasps’ power of reasoning, I thought their escape was now probable. Those who had just entered would surely show the way; they would teach the others to dig below the wall of glass. I was too hasty. Of learning by experience or example there was not a sign. Inside the glass not an attempt was made to dig a tunnel. The insect population whirled round and round, but showed no enterprise. They floundered about, while every day numbers died from famine and heat. At the end of a week not one was left alive. A heap of corpses covered the ground. The Wasps returning from the field could find their way in, because the power of scenting their house through the soil, and searching for it, is one of their natural instincts, one of the means of defence given to them. There is no need for thought or reasoning here: the earthy obstacle has been familiar to every Wasp since Wasps first came into the world.