fledged, when the nest suddenly became a bit of purgatory. The birds
kept their places in their burning bed till they could hold no longer,
when they leaped forth and fell dead upon the ground.

After a delay of a week or more, during which I imagine the parent
birds purified themselves by every means known to them, the couple
built another nest a few yards from the first, and proceeded to rear
a second brood; but the new nest developed into the same bed of torment
that the first did, and the three young birds, nearly ready to fly,
perished as they sat within it. The parent birds then left the place
as if it had been accursed.

I imagine the smaller birds have an enemy in our native white-footed
mouse, though I have not proof enough to convict him. But one season
the nest of a chickadee which I was observing was broken up in a
position where nothing but a mouse could have reached it. The bird had
chosen a cavity in the limb of an apple-tree which stood but a few
yards from the house. The cavity was deep, and the entrance to it,
which was ten feet from the ground, was small. Barely light enough was
admitted, when the sun was in the most favorable position, to enable
one to make out the number of eggs, which was six, at the bottom of
the dim interior. While one was peering in and trying to get his head
out of his own light, the bird would startle him by a queer kind of
puffing sound. She would not leave her nest like most birds, but
really tried to blow or scare the intruder away; and after repeated
experiments I could hardly refrain from jerking my head back when that
little explosion of sound came up from the dark interior. One night,
when incubation was about half finished, the nest was harried.
A slight trace of hair or fur at the entrance led me to infer that some
small animal was the robber. A weasel might have done it, as they