Watching one of these busy companies of small birds at work, one is amazed at the thought of the abundance of larval insect life in these oak woods. The caterpillars must be devoured in tens of thousands every day for some weeks, yet when the time comes one is amazed again at the numbers that have survived to know a winged life. On July evenings with the low sun shining on the green oaks at this place I have seen the trees covered as with a pale silvery mist--a mist composed of myriads of small white and pale-grey moths fluttering about the oak foliage. Yet it is probable that all the birds eat is but a small fraction of the entire number destroyed. The rapacious insects are in myriads too, and are most of them at war with the soft-bodied caterpillars. The earth under the bed of dead leaves is full of them, and the surface is hunted over all day by the wood or horse ants--_Formica rufa_. One day, standing still to watch a number of these ants moving about in all directions over the ground, I saw a green {93} geometer caterpillar fall from an oak leaf above to the earth, and no sooner had it dropped than an ant saw and attacked it, seizing it at one end of its body with his jaws. The caterpillar threw itself into a horseshoe form, and then, violently jerking its body round, flung the ant away to a distance of a couple of inches. But the attack was renewed, and three times the ant was thrown violently off; then another ant came, and he, too, was twice thrown off; then a third ant joined in the fight, and when all three had fastened their jaws on their victim the struggle ceased, and the caterpillar was dragged away. That is the fate of most caterpillars that come to the ground. But the ants ascend the trees; you see them going up and coming down in thousands, and you find on examination that they distribute themselves over the whole tree, even to the highest and farthest terminal twigs. And their numbers are incalculable--here in the Forest, at all events. Not only are their communities large, numbering hundreds of thousands in a nest, but their nests here are in hundreds, and it is not uncommon to find them in groups, three or four up to eight or ten, all within a distance of a few yards of one another. I had thought to write more, a whole chapter in fact, on this fascinating and puzzling insect--our "noble ant," as our old ant-lover Gould called it; but I have had to throw out that and much besides in order to keep this book within reasonable dimensions.