what on earth is this?

[AndyC]

I think they are made by bloodworms (chironomid larvae).
4cm sounds a bit long but I doubt the larvae are that big


Andy

[Gill Catton]

yes you're right! some sort of chironomid, I went back and broke open one of the tubes (sorry worm) they were quite rubbery to touch most perculiar.
The tubes were noticably shorter this time but it was much drier and indeed the track which was puddled along its whole length last time had only one puddle remaining which thankfully had these tubes! (though the puddle was more shallow and the external part of the tubes shorter, on pulling a tube up, it was clear that the tube continues into the substrate).

Apologies for the quality (or lack of) cor they are wiggley!! It took me 15 min to get these images!! After which I really had to get on with my work!!