Though housing preferences vary from species to species, there are some universal pitfalls to avoid when designing and installing birdhouses.
Sure, this two-story birdhouse is cute, but it displays several flaws. The bright-red roofs and light-reflecting mosaic serve as a beacon to predators: get your eggs and chicks here! The roofs are not designed to shed water away from the entry hole, nor do they have a long enough overhang to protect birds from mammals and sun. And the front landing perches give predators an unfair advantage when raiding nests. Birdhouse manufacturer Duncraft goes so far as to say, "The only useful birdhouse perches are for home decor—they make great hooks for keys."