For the last 100 years, scientists have tried to find whatever was responsible for the silky, thin strands of “ice” that form on decomposing wood on the forest floor. According to a recent report from Live Science, a new study has just about turned the mystery on its head. This “hair ice,” as researchers have come to know it, is apparently the work of a strange fungus that can flourish at low temperatures.

The phenomenon was first researched by Alfred Wegener, who was also famous for his theory on continental drift. In 1918, Wegener imagined that the strange ice formations were linked to the presence of mycelium, a fungus that thrives in rotting wood. As they suck nutrients from the wood, the mycelia form a pale, web-like sheen on the wood.

Nearly a century after Wegener wrote about hair ice, researchers just realizing how important these fungi are in the formation of hair ice. According to Christian Matzler of the Institute of Applied Physics at the University of Bern in Switzerland, the study’s co-author, “The same amount of ice is produced on wood with or without fungal activity, but without this activity, the ice forms a crustlike structure.”

The fungus makes the water freeze in thin strands that look eerily like hair – each strand measures just 0.01 millimeters in diameter. They help keep a constant temperature along the entire length of the strand, just around the freezing point of water.

The scientists noticed that one type of fungus appeared in every piece of rotting wood they tested – a species named Exidiopsis effuse. They also noticed trace amounts of lignin and tannin in their samples, compounds that attract various types of fungi. These fungi decompose lignin with the enzyme lignase, which makes the wood begin to rot. They also help hair ice keep its shape and grow into a surreal head of hair growing from debris on the forest floor.

The researchers will continue to study hair ice, and try to figure out exactly how the presence of fungus alters the physical properties of freezing water.