Earlier this spring, I put up some chickadee birdhouses in my yard. Lots of chickadees stopped by to check them out, but they never moved in. As it got later and later into the year, I began to lose hope that I would get any chickadees this season. I read online that chickadees usually nest around April or May. Once June arrived, I accepted the fact that I was unlucky this year, but maybe next year. However, on June 19th, I was pleasantly surprised to see a pair of chickadees flitting in and out of the birdhouse. They would go to a mossy tree in my yard and grab beakfuls of moss and take it back into the birdhouse. They did this all day. The next day I was eager to watch them build their nest further, but they never returned. I haven't seen them since. I looked in the birdhouse and there was lots of moss in the vague shape of a nest. It doesn't make sense to me that they would spend all day building a nest, only to disappear the next day out of the blue. Does anyone know of any possible reasons why the chickadees stopped building their nest halfway through?