When cozying up with would-be predators, cleaner shrimp follow a dependable script. Duke Today, June 20, 2018. It’s a mystery how cleaner shrimp partner with would-be fish predators — sometimes even climbing in their mouths — without getting eaten. A new study reveals how the shrimp convinces fish not to eat them, and the fish conveys that it’s a friend and not a foe. Picked up by National Geographic.