What should I do if House Wrens nest in a box I put up for bluebirds?

House Wrens are commonly implicated in the puncturing of eggs of other cavity-nesting species. For this reason, some nest box landlords prefer not to play host to House Wrens. If you prefer not to attract House Wrens, make sure your nest boxes are far from shrubs or woods. The more open the site, the better. Please remember that it is illegal and unethical to disturb the nest or eggs of any native bird species, including House Wrens. The only species that are not protected by law are the non-native European Starling and House (English) Sparrow.