But some egg-laying parasites go more than just skin deep. Tapeworms, for example, invade your intestines. Adults can stretch longer than a bowling lane and block up your digestive system.

Cysticercosis is caused by the larvae of the parasite Taenia solium, or pork tapeworm (stock photo) A man in the US who complained of frequent migraines was found to have tapeworm larvae in his ...