The larvae of a certain species of gnats have been known to migrate by assembling into a large snake-like shape numbering tens of thousands of individuals and crawling on the ground as one. The bizarre phenomenon is known as “Pleń” in Poland and “Heerwurm” in Germany.
As far back as the 17th century, the larvae of sciaria militaria, a species of dark-winged fungus gnats found throughout Central Europe, have been observed moving on the ground as a giant slithering unit ranging from 50 centimeters to a reported 10 meters. Called Pleń by the Polish people who first documented the rare and poorly understood phenomenon, this method of migration numbers between a few thousand to several tens of thousands of tiny larvae. They crawl on the ground as one unit, towards an unknown goal that scientists have so far only speculated on.
