The term "nits" actually describes the eggs of head lice. They're often the first sign of an infestation. And with one louse laying more than 100 in their month-long lifespan, there can be a lot of ...

Medically reviewed by William Truswell, MD Sea lice bites are an itchy rash caused by jellyfish larvae that get trapped in swimsuits after swimming in the ocean. The larvae release toxins that trigger ...