Opossums Sleep Hanging Upside Down by Their Tails

Adult opossums do not sleep hanging by their tails, because they simply cannot; a grown opossum is far too heavy for its tail muscles to hold its whole body weight for any length of time, let alone all night. They do have prehensile tails, which they use as a fifth limb for balance while climbing and for carrying bundles of nesting material, and young opossums can briefly hang for a few seconds. But sleeping suspended is a cartoon invention. Real opossums sleep curled up in dens, hollow logs, burrows, or leaf nests, the right way up like sensible mammals. The tail is a handy tool, not a coat hook. So the iconic image of an opossum snoozing upside down is physically impossible for the adults, which is a shame, because it is a genuinely excellent mental picture.