I don't think that is a growing habbit.
Sounds more like a bad habit. lol
Assuming he is not bored, no object in his paw, not sore, and
no allergy.
He might just be obsessed with licking and biting once
he starts up.
Once in awhile Rocky will start licking his paws.
Once he starts, he would
lick himself raw if I did not put a stop to it.
Once he does stop he goes on to something else
and forgets about his paw.
(I think with Rocky he gets bored or obsessed once he starts licking)