But most scientists call this tonic quiescence (TI).

Nicknamed "playing possum" after its star performer, feigning death is also called thanatosis. That’s from Thanatos, the ancient Greek deity of death. But most scientists call it tonic immobility, or TI. How and why TI occurs depends on the species and situation. Spewing stench and adopting odd postures are common and often play important roles. Other animals sacrifice their neighbors: quail chicks that freeze while their kin run amok have a better chance of survival when pursued by a cat.