Fish Will Eat Until They Die

I've got six neon tetras. I don't over feed them, but they still eat as much as they can as fast as they can. Sometimes they're bloated after feeding having added too much food, fouling the tank eventually.

There's one tetra who never bloats. He waits until the others are bloated with food, carves out territory and keeps it by attacking the bloated ones.

He's the only smart one, although it looks like another one is learning this.

They came as four and then two more added.

I'm going to buy two more.