Explain it as you may, it is a fact that the little bird shows this marked preference, makes this deliberate choice; and in the choice is protection and poetry, too. Doubtless he follows the guidance of a sure and watchful instinct. But who shall deny to him a share of the higher, finer things of the imagination? His life is like his home--gentle and sweet and idyllic. There is no happier spot in the summer woods than that about the birch of the chickadees; and none whose happiness you will be so little liable to disturb. Before the woods were in leaf last spring I found a pair of chickadees building in a birch along the edge of the swamp. They had just begun, having dug out only an inch of the cavity. It was very interesting to discover them doing the excavating themselves, for usually they refit some abandoned chamber or adapt to their needs some ready-made hole. The birch was a long, limbless cylinder of bark, broken off about fourteen feet up, and utterly rotten, the mere skin of a tree stuffed with dust. I could push my finger into it at any point. It was so weak that every time the birds lighted upon the top the whole stub wobbled and reeled. Surely they were building their house upon the sand! Any creature without wings would have known that. The birds, however, because they have wings, seem to have lost the sense of such insecurity, often placing their nests as if they expected the nests themselves to take wings and fly to safety when the rains descend and the winds come. This shaking stub of the chickadees was standing directly beneath a great overshadowing pine, where, if no partridge bumped into it, if two squirrels did not scamper up it together, if the crows nesting overhead in the pine did not discover it, if no strong wind bore down upon it from the meadow side, it might totter out the nesting-season. But it didn’t. The birds were leaving too much to luck. I knew it, and perhaps I should have pushed their card house down, then and there, and saved the greater ruin later. Perhaps so, but who was I to interfere in their labor? Both birds were at the work when I discovered them, and so busily at it that my coming up did not delay them for a single billful. It was not hard digging, but it was very slow, for Chickadee is neither carpenter nor mason. He has difficulty killing a hard-backed beetle. So, whenever you find him occupying a clean-walled cavity, with a neat, freshly chipped doorway, you may be sure that some woodpecker built the house, and not this short-billed, soft-tailed little tit. Chickadee lacks both the bill chisel and the tail brace. Perhaps the explanation of his fondness for birch trees lies here--because the birch trees die young and soon decay!