Torpor

Torpor is a state of markedly reduced physiological activity in an animal, typically marked by a lowered body temperature and metabolic rate, which allows the animal to conserve energy through periods when food is scarce. Short bouts lasting less than 24 hours are known as daily torpor and can occur at any time of year, while longer episodes lasting days to weeks, during which metabolic rate can fall below five percent of normal, are classified instead as hibernation in winter or aestivation in summer. Rather than being a simple shutdown of body temperature control, torpor is a well-regulated thermoregulatory state used by hummingbirds and other strisores among birds and by many marsupials, rodents, and bats among mammals, having apparently evolved independently multiple times as a way for small animals to survive difficult conditions. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/