I have this pleco(don't know much about plecos but its got whiskers growing off its nose and its a light brown color) that never moves out of this one spot. All it does is chill upsidedown on this rock and never moves, it's never on the glass and it's VERY skiddish, if it sees any action at all it freaks and goes back under the rock(in the once weekly event that it leaves the underside of this rock) Is this normal, I've never seen a pleco this skiddish. How can it get any food(algae) if it keeps sucking on the same rock all day?