Tree pine ("Pinus" species) the bark exudes sticky resin which deters attackers whereas in rubber trees ("Hevea brasiliensis") it is a milky latex that oozes out. The quinine bark tree ("Cinchona officinalis") contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta, Arecales, Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings. Although the bark functions as a protective barrier, it is itself attacked by boring insects such as beetles. These lay their eggs in crevices and the larvae chew their way through the cellulose
Bark hack Bark hack A bark hack is a tool used to remove pine tree bark to promote the flow of pine resin, which is used in naval stores production. The tool consists of a wooden shaft with a weighted butt and hook-like, replaceable, U-shaped blades at the head. The bark hack is swung much like an axe and is used to create a hatched chevron pattern ("cat face" or less frequently, a "blaze") into trees' exposed sapwood. The weighted end helps the operator follow through with the force necessary for the hooked blade to scoop out chips of hard pine wood.