Letter | Published:

Fellow-Feeling in House-Flies and Swallows


THE moral feelings of animals being as interesting as their intelligence, perhaps the readers of NATURE would care to hear of a curious instance that I just now witnessed of fellow-feeling in the common house-fly. A number of them had collected in the top of a window, and I was about to open it to let them out, when I saw a wasp seize one, as I have seen many seized this year, but never before, though I have often seen them feed greedily on maimed bees. The wasp was about to sever the head from the body of his victim, when a fly—by no means a large one—flung itself violently against the captured one, trying apparently to knock it away from the wasp; it did not attack the wasp. This was done again and again, whether by the same fly or another I could not tell, the action was so rapid; at last the body of the fly was knocked away, but the wasp retained the head and devoured it. It then grasped another, and again a fly dashed at it, and another, and another, though they were all evidently afraid of the wasp; and no wonder; it seemed very fierce and hungry. The action of the flies was quite unmistakable. I called another person to watch it with me, and she was as much surprised as I was, and inclined to kill the wasp; but I thought we could spare a few flies, notwithstanding this unexpected discovery of fine feeling in them, and I would not let her disturb the balance of Nature.

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