If you're a little shrimp or fish, the ocean can be a scary place. The water is full of sharks, eels and other predators looking to grab a seafood snack. So why do cleaner shrimp venture into the jaws of death? And why do remora fish boldly hitch a ride on sharks? That's because sometimes, a cleaning service is more important than a snack. The animals in this video help out their tough-guy friends by clearing away parasites and dead skin, along with some other surprising benefits. In return, the little critters get protection from becoming dinner. It's the ocean version of "you scratch my back, I'll scratch yours," as process known as symbiosis.