Which mammal is known for "playing dead" as a defense mechanism?

The Virginia opossum is the mammal famously known for “playing dead” as a defense mechanism. When threatened, it may first hiss, bare its teeth, drool, and try to look dangerous; if the threat continues, extreme fear can trigger an involuntary state of death-feigning.

A motionless opossum may lie on its side with its eyes and mouth open, tongue extended, and feet clenched. Its breathing becomes shallow and its heart rate can drop sharply, making the animal appear dead rather than merely still. The state may last for several hours and usually ends only after the danger has passed.

This behavior is the source of the expression “playing possum.” It can discourage predators that prefer live prey or are reluctant to approach a seemingly dead animal. The opossum may also release a foul-smelling anal fluid, adding another deterrent to the display.

A common misconception is that the animal consciously decides to perform this act whenever convenient. Death-feigning is generally an involuntary response to overwhelming fear. The Virginia opossum is also the only opossum species native to the United States and Canada, despite the broader use of “opossum” for many related marsupials in the Americas.