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10 animals that are bad for the environment

By: Bryan Nelson on April 14, 2010, 1:05 p.m.
Cane toads

Photo: Sam Fraser-Smith/Flickr

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Cane toads

Cane toads have become wildly successful as an invasive species in Oceania, the Caribbean and the United States. Ironically, they were purposely introduced to foreign habitats to eradicate agricultural pests, and in the process they became pests themselves. These South American natives are most dangerous to native wildlife because their poison glands are toxic to birds, mammals, fish and reptiles — and anything else that attempts to eat them.