Hello - maybe someone can shed some light on this odd thing my 2 year-old RES has just started doing. He has started furiously rubbing the top of his shell underneath the filter. He crawls underneath it and moves around like crazy -- it looks like he's scratching or rubbing the top of his shell against it. Back and forth for minutes at a time, like it's itching him or something. Has anyone seen anything like this? He can't feel the outside of his shell, can he? I see a little spot on it, a small mildly discolored area but I'm not sure if that's what he's itching or if it's discolored because he's scratching that spot. Any thoughts? Thank you!


