non-native species

I hear roughly an eighth of Australia is a great place to grow sugar cane. At some point, cane beetles from South America were accidentally imported, and some genius decided to import cane toads to eat the beetles. The cane toads proceeded to eat easier prey and didn't make much of a dent in the beetle population.

Cane toads are poisonous; they have venom sacks on their shoulders, and if you eat them, you die.

Nothing was making any kind of dent in the poisonous toad population until recently, when crows figured out that if you flip the toads over, you can eat them and not die.

Crows are smarter than I thought.