Since in the winter the surface temperature on a glacier could reach −40 C (−40 °F), scientists doubt the worms follow the diurnal pattern. The worms most likely remain below the surface. The snowfall provides insulation and the temperatures below maintain a stable 0 C (32 °F). Ice worms can still find plenty of algae in the firn layer, the layer of packed snow in transition to ice. Scientists know little about the ice worm during the winter as the inaccessibility of glaciers prevents further study.