On warm days, the sap also attracts insects, including large numbers of ants, an additional food source for the birds. Many woodpeckers also eat fruits, nuts, and even bark. Vegetable matter, including cherries and other fruits, seeds, beech nuts, acorns, and bark, makes up as much as two-thirds of its diet. Red-headeds also devour insects and arachnids on occasion, as well as the eggs and nestlings of other birds. In backyards, red-bellied woodpeckers often dine on offerings of suet and sunflower seed.
Woodpeckers lack the syrinx, or voice box, that characterizes songbirds.
Although they do vocalize, woodpecker calls lack the rich diversity of sound for which songbirds such as mockingbirds, nightingales, canaries, and orioles are famous. The order Piciformes includes woodpeckers, toucans, and barbets, with the family Picidae reserved for woodpeckers and Eurasia's two species of odd-looking wrynecks. North America hosts 22 species, including the seven that reside in or near Washington. Aside from their bills, woodpeckers' most valuable tools are their tongues. Once prey crawls into view or is exposed by excavation, the birds' long, flexible, bristle-tipped tongues go to work.