My daughter made a bluebird house in her 4-H class. We hung it near an open field away from trees. We hoped a lovely bluebird couple would move in and enjoy it, but the sparrows seem to have signed the mortgage papers first. It has a lid with hinges so that at the end of the season we can remove the nest and hopefully a bluebird will come in. I looked inside last week and saw nothing. Two days later my daughter looked in and saw an egg!