interesting alarm clock

Apparently during my last road trip I left the storm window outside my bedroom window cracked by about 1 1/2 inches. During my absence it would appear that a small family of nuthatches moved into that space. So I have taped down the blinds on that window and unplugged the lamp on the table next to the window, so they won't be spooked or disturbed. So every morning just after sunup I hear some rustling and then 3 or 4 little voices chirping and muttering. Followed by the parents leaving and returning to the nest several times. It would appear at the moment I don't actually need a real alarm clock :-)