During South America's rainy season, the rivers rise up to the treetops, bringing piranhas with them. A clumsy egret chick loses balance and plunges into the maelstrom.
South America has more than 20 species of piranha.
The most notorious is the red-bellied piranha...and they're about to earn their reputation.
In the rainy season, rivers crest their banks and flood the land.
The rain brings a bumper crop of prey: Great white egrets nesting in the only dry place left.
Awkward young egrets aren't ready to fly so if they lose their balance, they're goners.
Like sharks, piranha have sensors to detect other creatures' movements.
Once blood is shed, piranha can detect a drop from two miles away.
Thrashing only draws more piranha.
All that's left is pillow stuffing.