The cane toad is a large, warty, poisonous terrestrial amphibian that is one of the world's most destructive invasive species. Native to South and Central America, it is an opportunistic feeder, with a diet consisting largely of insects, but also including small birds, reptiles, other amphibians, small mammals, plants, dog and cat food, household waste, feces, and even dead animals.
Both the adult toads and their tadpoles can thrive in a wide range of habitats, and are particularly fond of those which have been altered by human activity. Cane toads are a prolific breeder, with females laying single-clump spawns of thousands of eggs. Moreover, they are protected from predators by their highly toxic skin and because they also toxic at the tadpole stage. Cane toads kill both pets and native species when the latter lick, bite, or eat them, and they outcompete native species for food and breeding habitat.
Cane toads were introduced into northeastern Australia in 1935 by the government at the request of plantation owners in an attempt to control cane beetles, which eat the roots of sugar cane plants. The initial batch of about 2,400 toads has exploded into millions, and their still-expanding range now covers thousands of square kilometers. Cane toads have also been introduced and spread into Florida, Hawaii, Guam, the Philippines, the Caribbean islands, Papua New Guinea and some western Pacific islands. There has been little progress on eradicating these toads to date despite the tremendous damage they do to biodiversity and their economic harm, and thus emphasis has been placed on restraining their further spread rather than eradication.