roundworm

There are hundreds of thousands of species of worms wriggling around the world. We made trading cards about six of them.

Scientist Peter Hotez has spent nearly 40 years trying to treat and eliminate the diseases that worms can cause. And he won't let the "ick" factor stop him.

Tapeworms, hookworms, leeches. Millions of specimens. This collection has it all — except legs.

Maybe. A nine-year study in Bolivia found an unexpected association between the parasitic worms in a woman's guts and her fertility.