Imagine a common ant scouring its habitat for food when it stumbles upon a snail’s slime balls. The ant chows down the snail slime, which, unbeknownst to it, contains the larvae of Dicrocoelium ...

Parasite, zombie, leech—these words are often used to describe people in unkind ways. Many of us recoil when ticks, tapeworms, fleas, head lice or bed bugs are even mentioned. Coming across such ...