On some glaciers, it's possible to find scattered colonies of mosses all around, each roughly the size of a snowball and shaped into slightly squashed spheres, with moss all around. They are called glacier mice and tend to occur in large groups.

They are also notable because they move across the ice, in a herd-life behaviour, rolling and constantly exposing new surfaces.

Scientists still don't understand very well how they form and how they move. They can persist for more than six years in the glacier environment.