Poison induced pica in rats.

Two experiments investigating the effects of poisoning on the consumption of non-nutritive substances are reported. In the first experiment, rats were poisoned with lithium chloride or Red Squill and offered a choice between food and soil. In the second experiment, rats were poisoned with cyclophosphamide and offered a choice between food and kaolin. Following treatment, poisoned rats in both experiments increased their consumption of the non-nutritive substances. Additionally, rats poisoned with logarithmic doses consumed amounts of the non-nutritive substances proportionate to the amount of poison administered. It was suggested that increased pica is an illness-response behavior of the rat, analogous to vomiting in other species, which can be used as an easily quantifiable behavioral assay of noxious drug effects.