Strychnine poisoning in animals usually occurs from ingestion of baits designed for use against gophers, moles, and coyotes. Strychnine is also used as a rodenticide, but is not specific to such unwanted pests and may kill other small animals. In the United States, most baits containing strychnine have been replaced with zinc phosphide baits since 1990. In the European Union, rodenticides with strychnine are forbidden since 2006. Some animals are immune to strychnine; usually these are species such as fruit bats that have evolved resistance to poisonous alkaloids in the fruit they eat. The drugstore beetle has a symbiotic gut yeast that allows it to digest pure strychnine.
