They are small ragworms. You can dig them in Estuary mud and they're apparently great for sticking in bunches on fine hooks. Good for flounder, bass, mullet.
Not sure if they can be dug in NE but I am sure some of the more experienced guys on this forum can help...(once they get back in from celebrating yet another convincing NUFC win down the pub(oh, yeah and SAFC too

))