Wood-boring insect larva tunneling through a piece of wood. A generic term for this sort of insect is 'woodworm'. The larvae feed for several years on the interior of wooden objects. They then pupate just under the surface and the adult form emerges. The adult form reproduces, and the female lays eggs in a wooden object, starting the life cycle once more. Here, the chewed up wood can be seen within the tunnel made by the larva, and the bark can be seen at top.