Chewing his foot?!

I was watching Henry the other night doing his usual ritual of 'enjoying himself'! When i looked closer though i noticed that he would alternate to chewing and what looks like cleaning one of his legs. He would then lick himself near the same leg, then go back to leg again. It was only the one leg he would chew on though.

Is this normal or is something wrong? Im booking him into the vets on monday to get one of his ears checked out (its got a small white patch on it and looks a bit 'lumpy'. The other ear is fine), could it be related?