mothraeve...you are so wrong. It is better to not put up birdhouses then to put poorly mounted houses which put the birds in danger. Houses should be mounted on slick metal poles with predator baffles. Why on earth would you want to put up a house just to have birds move in and then have the eggs or babies eaten????? Do you realize an incuating female is also in danger if a raccoon finds your houses? A raccoon can and will eat an incubating female bird if it raids the nest at the right time. You need to check out sialis.org for information on properly offering nestboxes. Just because you havn't had a problem yet doesn't mean it won't happen. In nature like it a natural cavity if a predator gets a bird, well that is nature. If it happens in a poorly mounted nestbox, that isn't nature, it is the fault of the person putting up the nestboxes. Just because lots of people put them up improperly and endanger the birds by doing so doesn't mean that you should give advice that it is ok to do this. It isn't ok to put birdhouses on trees of fences! You should take your boxes down if that is the way you think. Plus unless you actually monitor your nestboxes you would have no way of knowing if the nesting actually succeeded or not.

I would try again if you have wrens in your area. Some birds just take longer to figure it out than others. I know it is gut wrenching to watch but it is for their own good. I've had to take it off too and try again so don't feel bad. Does it have sides? No sides does help at first but I recommend adding them. I have seen wrens repeatedly crawling all over a box trying to find a way in. I've done this for 6 or 7 years now and the Blues always find a way in eventually. I had a female last year that was not getting it at all. I had to cut a flap in the guard right in front of the hole and tape it back so she could see the hole and when she got used to that I taped it back down. Is there at least 2 1/2" in front. I leave 3" at least until they get used to it. Good Luck Cathy

I replaced an old wren nesting box with a Black Capped Chickadee nesting box and while I was at it I thought I would also install a nature/bird cam. Hopefully its not to late in the season to attract a nesting pair. Here is a link that might be useful: Installing nesting box and bird cam

As lisa likes to say....I don't think any bird police are going to be coming by your place if you remove that egg and nest. That is what I would do...but that is up to you. If you let them nest then there will be approx 7 more wrens to deal with next year....