Needle ice is also known as pipkrake, a word derived from the Swedish words pip, a musical tube, and krake, frozen ground. A musical tube in the frozen ground. The small, intricate, needle-like spicules form in moist, heavy soils in fall, winter, and spring, and act as agents of erosion. Water drawn toward the surface freezes into thin, tiny slivers that loosen the surrounding ground into ice ﬂakes and chunks. Needle ice is a type of ground ice, but the term is sometimes used as a synonym for candle ice, especially when the “candles” are relatively short and narrow. Some also apply the term to random concentrations of small, sharp spicules that occasionally form on the surface of sea ice, creating a painful bed of nails for sled dogs.