My point is not to settle the quest

My point is not to settle the question of the concrete reasons why natural selection has favoured the evolution of thanatosis as a defence mechanism. What I want to argue is that, if thanatosis has evolved, it’s because there are some advantages – regardless of the concrete form they take – to appearing specifically as though one were dead. What is there in common to lying belly-up completely still, not responding to interactions, with eyes and mouth wide open, while secreting blood and defecating? What is there in common to having a blue tongue, smelling rotten, being cold and not exhibiting signs of breathing? The only possible explanation to why these characteristics occur together as part of the same behaviour is that the animals are feigning death.