do you play with him? my boy used to attack my ankles, back when i first brought him home. turned out he was bored. got a bunch of interactive toys and started playing with him and he mellowed out nicely.
this is, of course, assuming that he’s clear of any medical issues. he’s been to the vet recently, right? 🙂
honestly, i’d talk to a behaviorist about this. they can assess your dog’s behavior firsthand and suggest things accordingly.