“They are beetles,” Uncle George replied, “and they do resemble little row-boats—so much so that they are called ‘water boatmen.’ This beetle’s body is shaped like a boat, and he lies on his back and moves his very long hind legs exactly like oars. He has a large, sharp beak, which you can see if you look closely.”
Just as Uncle George was speaking, a small fly alighted on the surface of the water. It was immediately seized by a water boatman, who dived with it to the bottom of the tank.
1. Water Boatman. 2. Water Whelk. 3. Water Hog Louse.
“That is how the creature feeds,” said Uncle George. “When an unlucky fly comes near, he seizes it with his two fore pairs of short legs, drives his cruel beak deep into its body, and dives with it to the bottom of the pool. When he has drowned his victim, he devours it at leisure.
“But let us look at the creature I first spoke of—the larva of the diving beetle.”
There were several in the tank. Uncle George lifted one out with a small gauze net. He placed it in a saucer of water and asked the boys to sketch it.
“It has six legs,” said Frank. “Its head is large and flat, and there are two things like horns sticking out of it.”
“These are the creature’s jaws,” said his uncle.
Uncle George touched the creature’s head with the point of his pencil. Instantly the long, curved fangs moved apart, and the creature sprang at the pencil and closed its fangs upon the wood.