This is a GREAT video. Mine were mostly always brown and greatly varied in length and width. But anyway.
Doc Sutter said that the biting sensation happens when the worms let go. He claims when they latch on they secrete an anasthetic and the host does not feel this. When I watched your clip of that little bugger who holds on despite a huge swirling vortex of water.... well makes sense.
Thanks very much for this! Hubby is still muttering under his breath and shaking his head.