Our concept of death is one of those characteristics, like culture, rationality, language or morality, that have traditionally been taken as definitional of the human species – setting us apart from the natural world and justifying our boundless use and exploitation of it.
However… the human concept of death is not necessarily the only concept of death.
The Virginia opossum is probably the animal with the most elaborate thanatosis [death] display (hence the expression ‘to play possum’).
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This does not mean that opossums themselves necessarily have a concept of death, or that they behave this way with the intention of being mistaken for a corpse.
On the contrary, it appears to be a genetically inherited behaviour that does not require any learning and that is triggered automatically upon the detection of certain stimuli.
What this does mean, however, is that the predators’ concept of death was the likely selection pressure that shaped these displays.
Maybe opossums lack a concept of death, but we can be pretty sure that the animals who intended to feed on them throughout their evolutionary history did tend to have one.