Q:
I have a 5-month-old Peek-a-Poo puppy that likes to bite. How do you cure this habit?
A: Biting can have a number of different motivations, and with your quick question and not much description of the behavior, it's hard to know exactly what the biting is about. You say your pup “likes to bite,” which sounds more as if he does it for fun than to intimidate or hurt you. I'm going to take his age and developmental stage as a clue to what's happening. Considering these points, I'd guess he's probably a fairly normal pup who just needs to learn more appropriate play behavior.
Puppies learn about life's rules through play, and your pup needs to learn that people don't appreciate being bitten. If you've been playing hand-mouth tag with your puppy, quit that right away. When you play with your pup, keep a toy handy, and if he starts to bite you, redirect his attention to the toy and encourage him to bite that instead.
If that doesn't work and he keeps trying to bite you, end the game. Fold your arms across your chest and turn away from the pup. You may even need to leave the room, to give him a short time-out to calm down. This time-out only needs to last 30 seconds or a minute to be effective. He'll quickly realize he's lost his playmate (you) and will try to play more gently when you come back. If he renews his biting when you return, leave again.
Some pups get irritable and 'bitey' when they're hungry or sleepy. If your pup won't stop biting you and it's been a while since he's eaten or napped, feed him a snack in his sleeping area and leave him alone for 10 minutes. Then quietly check in on him and if he's resting, don't disturb him. Puppies, like human toddlers, do need regular naptimes to stay sweet-tempered all day.