Certain small mammals, such as hedgehogs, bats, and dormice, are called true hibernators because they spend most of the winter in a state similar to death, their body temperature approximating that of the environment.
Mamalia kecil tertentu, seperti landak, kelelawar, dan tikus kecil (famili Gliridae), disebut hibernator sejati karena mereka menghabiskan sebagian besar musim dingin dalam keadaan mirip mati, dan temperatur tubuh mereka mendekati temperatur lingkungannya.