Filmed this today, lucky to catch it.
It would appear to be an Aeolosoma, though which out of the named ones, if indeed any of them, I leave to the experts.
http://www.faunaeur.org/full_results.php?id=54222
https://www.youtube.com/watch?v=HaW8u5ZpfiA
Oligochaeta Feeding Cycle
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