It was not long before the female became so accustomed to the snap of the shutter that in order to prevent her from entering the nest I was forced to rush out from my hiding place; but at last, apparently becoming desperate, she succeeded in returning to her eggs in spite of my best efforts to prevent her. There now ensued a very interesting change in the bird’s action. It will be remembered that at first she had left the nest on hearing me approach, while a light tap brought her through the opening with startling promptness. But now, evidently realizing that a return to her duties of incubation could be made only at great risk, she determined under no conditions to leave her eggs. In vain I rapped at her door and shook her dwelling to its foundations; no bird appeared, and not believing it possible that under the circumstances she would remain within the stub, I felt that she must have left without my knowledge, and therefore retired to await her reappearance. [Illustration: 28. Chickadee at nest hole.] At the end of several minutes the male, with food in his bill, advanced cautiously, and clinging to the rim of the nest opening, hung there a moment and departed minus the food. This was surprising. Could there be young in the nest? or was the bird, in imitation of the Hornbill, feeding his imprisoned mate? I rapped again, and this time, perhaps taken unawares, the female answered my question by appearing. On June 3d a family arrived in the Chickadee villa, and both birds were found actively engaged in administering to its wants. As a return for the inconvenience to which they had been subjected, a perch was erected by way of a step at their door. The female was appreciative and at once availed herself of this means of entering her home.^{28} The male, however, as before, was more wary. He had braved the camera to bring food to his mate, but his offspring had apparently not so strong a claim upon him. He would fly off in search of food and shortly return with a caterpillar, then perch quietly for several minutes a few yards from the nest, when, repelled by the camera and attracted by the food in his bill, he yielded to temptation, devoured the caterpillar, vigorously wiped his bill, at once started to forage for more food, and returned with it only to repeat his previous performance. Occasionally he uttered a low whistle, addressed presumably to the female, and at times a _chickadee-dee-dee_, which I interpreted as a protest to me, and both notes were also uttered by the female. The latter took so kindly to the doorstep that it was determined to give her a door, and to this end a leaf was pinned over the entrance to her home in such a manner that it swung to and fro, like the latch to a keyhole. This clearly did not meet with her approval, and at first she seemed puzzled to account for the apparent disappearance of the nest opening. But in less than a minute she solved the mystery, pushed the leaf to one side, and disappeared within.