Tonic Immobility

Tonic immobility is a natural state of paralysis which animals enter. This is similar to hypnosis. The species that I thought was the most interesting to learn about was the tonic immobility of sharks. It can be induced by stimulating the tiny sensory pores on their snout. Tonic immobility is primarily used by researchers to subdue sharks so they can study them without struggling and threat of injury. One animal that uses tonic immobility to its advantage is the orca. Research suggests that orcas may have mastered how to induce tonic immobility among sharks. Orcas also use this technique when hunting stingrays as well. Mastering this skill has lead to a large increase in successful orca attacks on sharks. 

http://awesci.com/killer-whales-ingenious-trick-to-kill-sharks/