You might think that the surface of a glacier is just ice. You would be wrong. Glacier ice is teeming with mysterious life forms. One of the more unusual kinds scattered across the Root Glacier in Iceland are some strange fuzzballs which scientists call “glacier mice.”
These are in fact balls consisting of different kinds of moss that probably formed around dust or stone. No one has got to the bottom of why they appeared but some time ago, scientists studied their movement and found that conditions had to be just right for them to move in mass formation. They have been tracked over several years and although the expectation was that they perhaps rolled downhill or in the direction of the wind or sun, that was not the case. They are apparently capable of moving an inch a day but so far, no one knows why or how.
Source: NPR.org