Woodpeckers are attractive, interesting visitors to bird feeders and yards. In addition to adding beauty to the landscape, woodpeckers are an integral part of the ecosystem. Woodpeckers are primary cavity nesters, which means that they use their bills (and reinforced skull structure) to excavate holes into dead wood. Woodpeckers use the cavities they create for nesting and roosting, but a wide assortment of other animals (secondary cavity users) like squirrels, raccoons, bluebirds, and owls, to name a few, will enlarge and use the cavities woodpeckers have created and abandoned. Thus, woodpeckers provide habitat for a host of other species. In addition, they feed on a variety of insects, helping to keep those populations in check.