My new adolescent dog likes to bite feet! :O?

I got a new dog this past Friday. He's half German Shepherd, half Husky and he's 8 months old. He seems to be an incredibly intelligent dog (he learned to sit the very first day I had him!), but also very energetic and playful. He's great at knowing when to stop playing moast of the time, except when he gets over-excited and starts chomping at my feet, my mom's feet, my brother's feet, and even my other dog's feet! When I give him a tap with my foot on the jaw to correct him ,he bites even more. I know it's still puppy play, but how can I hep stop it?