MOSS! BUT THE SAME ONE.

[image credit]

That's right - it's glacier mice. One of my favorite things maybe on the entire planet. Let's talk about these freaky fuzzy little rats!!

Glacier mice are balls of moss that live in large herds like this in a few select glaciers. They are moss all the way through, with a center consisting of dead moss matter, implying that they begin as small growths of moss and simply accumulate over time, like snowballs. However, their outside surface is alive and well on all sides. Glacier mice have been observed, through tagging and tracking, to roll across the glacier like a majestic herd of wildebeest, exposing all of their sides to the sunlight. They trundle along at a pace of about 2.5 cm per day. That's 30 feet in a year! They're really schmovin'! Certainly further than most mosses can claim to travel.

What's really exciting, though, is that they all move in the same direction, and we're not sure why or how. Scientists experimented to try and attribute their coordinated behavior to wind, sunlight, and the direction that their grazing ground slopes, but to no avail. They speed up, slow down, and change direction in unison, based on some mysterious moss code that we haven't cracked yet.

Cross-section of a glacier mouse. Note the dead moss matter inside, and the short gametophytes on the outside, adapted to harsh winds and sunlight. [image credit]

We have figured out how they roll, though - while the moss ball sits on the ice, it insulates the ice directly underneath it, protecting it from melting. This forms a little pillar of ice that the moss eventually rolls off of. The insulating power of glacier mice also gives it the wonderful ability to host all kinds of microorganisms that otherwise wouldn't survive the glacier's harsh conditions, and their ability to move makes it possible for microorganisms to spread from one habitable spot to another. They're like a bunch of little tardigrade passenger ships, braving the dangerous glacier to go where no water bear has gone before!!

Glacier mice have been found to consist of several moss species, most of which must reproduce asexually in order to survive in the dry climate. They've been observed to live for at least six years, but are projected to live much, much longer. I love them. So much. I hope they know that I love them!! I LOVE THEM!!!!