Some have postulated that thanatosi

Some have postulated that thanatosis works not as an anti-recognition mechanism, but as an anti-subjugation mechanism that prevents the predator from actually killing the animal. The idea is that thanatosis makes the predator believe that the prey has already died, therefore relaxing the predator’s attention and giving the prey a chance of escaping. Some predators treat their prey relatively gently or might release them for some minutes before consuming them, especially if they’re trying to kill more than a single animal in one go. Others will cache their prey for some time after having killed them. So perhaps feigning death can allow an animal to escape unharmed in such situations.