Tree spiking involves hammering a metal rod, nail, or other material into a tree trunk, either inserting it at the base of the trunk where a logger might be expected to cut into the tree, or higher up where it would affect the saw mill later processing the wood. It is a tactic used to discourage logging, either by creating a mantrap which may injure or kill lumberjacks who attempt to cut down the tree, or to damage the sawmill equipment later processing the wood. Furthermore, the presence of the spike reduces the commercial value of the wood by causing discoloration, thereby reducing the economic viability of logging in the long term, while not threatening the life of the tree.