They start out small, experimenting with eating a bit of meat by munching on the tiny shrimp that also occupy the pond. Within days, they graduate with honors from Carnivore College and begin their transformation from Tadpole Jekyll to Froggy Hyde. They grow much faster than their algae-chomping counterparts, and their jaws get bigger and stronger. Their digestive tracts shorten in preparation for an all-meat diet, and their tails grow more powerful. Within a week, the normal tadpoles have mutated into 'roided up monsters.
Which is when the cannibalism begins.
These killer tadpoles now see anything that moves as food, up to and very much including their own kin. And they couldn't stop even if they wanted to -- they are slaves to their hunger. It's like some sort of gypsy curse: forced to keep eating meat, any meat, family meat, or they'll quickly revert back to their smaller, weaker state and fall prey to the other monsters.
The weaker tadpoles are essentially powerless. They're almost a whole different animal. They're just down there, sucking algae at the bottom of the pond, thinking all is well, and then Jeff comes over to borrow a cup of sugar ...
National Wildlife Foundation
"Nice liver. Mind if I borrow it?"