The yellow-bellied sapsucker bird (Sphyrapicus varius) can cause damage to many species of trees by drilling one-quarter-inch holes through the bark of tree trunks and limbs in vertical and horizontal rows. These holes are often arranged so perfectly that you might think the bird used a ruler to make the placement. Often confused with wood borer damage, the holes caused by a sapsucker fill with sap, and the bird uses its brush-like tongue to draw out the sap. Will this damage kill your tree? Repeated attacks can girdle and kill branches or even the entire tree. The biggest concern is that wood decay or bacteria may enter through the feeding wounds. To discourage sapsucker feeding damage on a yard tree, wrap aluminum flashing or burlap around the tapped area. Often treatment of these tapped areas forces the bird to go somewhere else. Legally, this bird species is federally protected so avoid using gooey repellents such as Tanglefoot as they may injure the bird. There are possible insect culprits, however. If the holes go into the wood very deep, they would probably be made by insects or by woodpeckers of some kind going after insects. If they are on the surface only, it is entirely possible that they could be made by woodpeckers. An insect infestation would not bode well for the tree’s health.