Yet thanks to some painstaking sub-zero surveillance, these mossy blobs are slowly giving up their secrets. Those lucky enough to have encountered a colony in one of their remote icy haunts confess that they find them puzzling in many ways, not least their curious movements. Hotaling is one of the scientists who served up the latest instalment in the long-running saga of the glacier mice, which remain a riddle wrapped in a mystery. “They genuinely look cute, like a small furry creature – at least from a distance,” says Scott Hotaling, a glacier biologist at Washington State University. But when the Icelandic glaciologist JÓn EythÓrsson first brought them to the world’s attention in 1951, he dubbed them jökla-mýs (glacier mice) and it stuck.

Purists might call them unattached moss polsters, supraglacial globular moss cushions or just plain moss balls. If so, you will know that the mice in question aren’t actually mice at all. You may recall the tales of ice-dancing mice that travel in troupes and move with a synchrony worthy of the corps de ballet. Yet the elusive glacier mouse – small, green and fuzzy – suddenly found itself an A-list celebrity earlier this year when reports of its antics became the antidote to a blizzard of bad news. “Glacier mice” usually grow to 10 centimetres, but can be twice as bigįEW have glimpsed them in the wild and you won’t see any in captivity.

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