This teaming mass of worms 1.5cm long moves forward very slowly en masse. I suspect they need each others mucus to avoid drying out. It may also be a strategy to make them look like something else rather than individual worms to birds or other predators. I wonder what they are.
These are larvae of a fly in the family Sciaridae (dark-winged fungus gnats). These mass movements appear to be uncommon, but have been noted in other parts of the world, including North America and Europe. The reason behind this behavior remains poorly understood - see https://www.uaf.edu/museum/collections/ento/projects/sciara-larvae/
Very interesting! Thank you very much.
