Thanks eveyone, I am happier knowing that others do this also, don't want the only freaky clown knife in the galaxy!
I have noticed that he particulary likes moving the stones where I lay the lettuce for the pleco, at first I thought he disliked the smell or something, but now I watch him turn on his side and scrape his whole body lightly across the same area, almost like taking a lettuce smelling bath. Very odd......
