Acorn woodpeckers are primarily black, with patches of white on their faces and wings, with a bit of red on their heads. They are found in oak woodlands along the Pacific coast, from Washington to Colombia in South America. True to their name, acorn woodpeckers eat acorns, which they stash in holes they drill in trees. Some of these holes contain thousands of acorns! They also munch on flying insects. Woodpeckers live in communal groups of about a dozen individuals, who contribute by gathering food and raising young. The breeding relationships are complicated, with several males and females mating in each group.