Ice Crawlers can leave behind many drag marks crisscrossed on areas of the glacier not unlike those of the foothill-dwelling Keeled Sliders. The scale of the tracks and the forelimb strokes are dissimilar, however, and the two species are as well. There will also be innumerable small tunnel openings in the ice cliffs. They occur in clusters but there seems to be no obvious pattern to their distribution. These creatures can be found on the foreboding expanse of the glacier's surface in large groups (usually 30-odd). From a distance of some 50 kilometers away they might be mistaken for blocks of ice instead of life forms. Each individual Ice Crawler, while found motionless in their winter hibernation, is imbedded in a translucent sac which, in turn, can be frozen to the glacier's surface. These sacs are roughly three meters long, smooth, rigid, and ovoid. They appear to have been in place for some time. Though the sacs are somewhat translucent, it is difficult to discern the shapes of the core-creatures within. Something can sometimes be seen to stir, but scanners of the Expedition have given back only the weakest of signals, most of the scanner beams bouncing off of the strange, impermeable sacs. Weeks pass and by early arctic spring most Ice Crawlers in a group will be gone, leaving only a small number of individuals behind in the same spot. All but one or two of these left-behind individuals will be free of their sacs and their transformation is remarkable.