We've noticed that the tree swallows have decided to take over the bluebird nesting box. At first we thought they were moving in to an empty box...left last week when the bluebirds fledged. But, much to our distress, they're moving in when eggs are there. We looked in yesterday to see what was going on and much to our surprise, found that there were new bluebird eggs in the box. We left them there thinking that the bluebird parents would continue to shoo away the swallows, but this morning it seems the swallows have won...they're going inside. We're very distressed about it. I guess we'll peek in again today and see what's happening.