He usually lays around like a big slug then comes out at feeding time hovering just off the bottom. Tonight I walk by and he is swimming mid level, going back and forth, freaking everyone out.
Don't mean to worry you, but odd behavior can be an indication of illness. For example, recently I had a Queen Arabesque Pleco die a few hours after it started showing more activity than was usual. Everything it was doing was well within the bounds of normal Pleco behavior, aside from the fact that it was moving around more.