The Moscow Zoo has found a way to make its jerboas — a small rodent species — go into hibernation, saying the key is to make them "despair" in an ordinary fridge.
In a statement on its Facebook page on Wednesday, the zoo said only "extreme conditions," presumably those similar to their native desert habitats, would send jerboas to sleep, adding that any food or materials they could use to build a nest would give them "hope."
"That's why they are locked up in the dark, in silence, at a temperature of 3 to 4 degrees [Celsius]. That's when they despair and go into hibernation," the statement said.
Jerboas are nocturnal animals that hop around on two legs and live mainly in the deserts of northern Africa and Asia.