The great North American Locust Plague
Locusts are grasshoppers with some rather unique abilities. Overcrowding triggers their instinct to literally transform themselves.They change their color from green to brown, get more muscular, eat more, mate more and congregate in crowds. After their transformation, they traverse the land searching for food, colonizing breeding grounds.
Around dozen species of locusts have been discovered so far, but only one species live in North America – the Rocky Mountain locust.