Why it happens
Puppies explore with their mouths, teethe for months, and play with littermates using teeth. Hands, sleeves and ankles are simply the most interesting moving targets in the house.
What works
Redirect onto something legal every single time — a tug, a chew, a toy you keep in each room. End the interaction calmly when teeth land on skin: stand up, disengage, wait a beat, resume. Puppies learn that teeth end the fun.
Most importantly, watch the clock. The overwhelming majority of extreme biting is an overtired puppy. A puppy that age needs an enormous amount of sleep, and enforced naps in a crate eliminate more biting than any correction.
What makes it worse
Wrestling with hands, pushing the puppy away with your palms, shouting, and letting the puppy get overtired and overstimulated day after day.
Every dog is different. If you want a recommendation for your dog specifically, tell us what's going on and we'll point you to the right program — we're at 8618 Ridgefield Rd, Crystal Lake, IL.