Poison shyness, also called conditioned food aversion, is the avoidance of a toxic substance by an animal that has previously ingested that substance. Animals learn an association between stimulus characteristics, usually the taste or odor, of a toxic substance and the illness it produces; this allows them to detect and avoid the substance. Poison shyness occurs as an evolutionary adaptation in many animals, most prominently in generalists that feed on many different materials. It is often called bait shyness when it occurs during attempts at pest control of insects and animals. If the pest ingests the poison bait at sublethal doses, it typically detects and avoids the bait, rendering the bait ineffective.[1][2]