This is what a crab sees when a stingray is trying to eat it 😯   A four-metre stingray can eat 50 crabs a day, so this army of crabs work together to avoid being on the menu - and that includes a fake spy crab!   Spy in the Ocean is available on iPlayer in the UK and will be available on PBS in the US in the autumn. . . . . #SpyInTheOcean #Crabs #Stingray #Robots