Many people put up nest boxes with the best intentions of doing the right thing, but for various reasons, after a time the houses go unchecked and forgotten. It is tempting to think, “I put up a box; the birds can take care of themselves; I’ll leave it up to nature.” Other folks with good intentions will put up a box in a habitat that is inappropriate for the species they are trying to attract, and/or is susceptible to hostile takeover by house sparrows (non-native predators) and simply give up, allowing the house sparrows to win. Unfortunately, allowing these scenarios to play out does far more harm to ALL native cavity nesting birds, not just bluebirds. It is best to simply take down an unmonitored box or plug up the entrance holes. We encourage you to learn more about house sparrows and other predators before you put up ANY box.