glacier mouse

Calque of Icelandic jökla-mýs. Coined by geologist Jón Eythórsson in 1950. The Icelandic term appears only in plural form.

glacier mouse (plural glacier mice)

1. (usually in the plural) A ball of moss, often surrounding a rock, that moves across a glacier.
   • 1950, Jón Eythórsson, “Jökla-mýs”, in Journal of Glaciology, volume 1, number 9, →DOI, page 503:

     I call these mossy balls Jökla-mýs, literally "glacier mice," and you will have noted, Sir, that rolling stones can gather moss.

   • 2014, James H. Dickson, Robert E. Johnson, “Mosses and the beginning of plant succession on the Walker Glacier, southeastern Alaska”, in Lindbergia, volume 37, number 2, →DOI, pages 60–65:

     Such glacier mice are more or less spheroidal mosses which lie unattached on the ice surface.

   • 2020 May 22, Nell Greenfieldboyce, “Herd Of Fuzzy Green 'Glacier Mice' Baffles Scientists”, in NPR‎:

     Glacier mice can be composed of different moss species.