I found a small valley in the Brecons with thousands of these springtails hopping about on the snow.
No interactions present.
I know in Canada there is a species of springtail (Hypogastrura nivicola) that can be found in large numbers on snow. Maybe this is related to that species. Interesting observation.
They are incredibly common on snow, apparently. This is the first winter I have looked for insects on snow, but I was finding them every few inches, wherever I looked. No idea on the species, though...hopefully, someone will know more.
My Flickr photos...
Lat/Lng: 51.872, -3.4656
OS grid ref: SN991202