Perfecting the art of reproduction have made parasites the most successful life form on the planet. There are some who are violent, manipulative and have taken sex to the extreme. These parasites are sex maniacs.

A New Jersey woman finds her apartment infested with one of the most ubiquitous parasites on earth — bed bugs. Part of the reason for their success is the males' aggressive approach to sex, a method known as "traumatic insemination." A cyclist from Colorado discovers that the insect bites on his head are from botflies. In Oklahoma, a chemical sprayer's cough turns out to be the result of parasitic worms that multiply in the human lung.