When winter comes, they go down to the bottom of the pond and bury themselves in the mud. They lie there without moving or breathing until spring, when out they come, as lively as ever.
Yes, certain other animals pass the winter in this way; the bears, for instance, find a snug den and sleep all through the coldest winter weather. We call this winter sleep of animals hibernation, and many of the insects hibernate.
Yes, Ned, hibernating animals can get on with very little air; they sometimes seem to need none at all, and they take no food.
May wants to know what these queer water boatmen eat.
They suck out the juices of other insects.
They must lay their eggs in the water, little Nell thinks.
And so they do, on water plants.
Near the city of Mexico there are species that lay enormous quantities of eggs in the ponds, and what do you think? The Indians mix these eggs with meal, make them into cakes, and eat them.
The Mexican bugs are gathered by the ton, too, and sent to England as food for cage birds, fish, and poultry.
Little Nell thinks there must be a great many bugs in a ton. Indeed, there are, probably about twenty-five millions of them; so you can imagine Mexico is well supplied with water boatmen!