They typically sleep about 16-17 hours a day; that’s a lot!
Animal dander would be the answer you're looking for.
Hope this helps :)
Bones teeth and maybe scull
Streams that flow beneath melting glaciers leave long ridges of layered sediments, known as Esker. Eskers are formed within ice-walled tunnels by streams which flowed within and under glaciers. They tended to form around the time of the glacial maximum when the glacier was slow and sluggish and after the retaining ice walls melted away, stream deposits remained as long winding ridges.
