Biomagnification

Biomagnification is when tiny amounts of bad things like chemicals or poisons get into the water or the ground, and then small animals drink or eat the bad things, but the bad things don't go away. Instead, they stay inside the animals. When bigger animals eat lots of the smaller animals, they get all the bad things that the smaller animals had inside them. And then, when even bigger animals eat lots of the medium-sized animals, they get all the bad things that they had inside them too! So, the bigger the animal, the more bad things it has. That's biomagnification! It's like a bad chain reaction.