dog bite

my lab pup is two months old.it's a month we got her home.she is biting really hard.my questions are:
how long will she bite?
we put muzzle when she gets aggressive.she gets calm.is it good way to control her?

[Aleda M Cheng, D.V.M., C.V.A]

It sounds as if your puppy is trying to establish dominance in the pack order.  

The members of your family are just other members in your puppy's pack and she wants to be the alpha pack member.  This behavior must be eliminated while she is still a puppy.  Everyone in your household that comes in contact with your puppy must show that they are dominant.  This will take determination and compliance on your and other family member's parts.  

The steps to ameliorate adverse behaviors involve correction and reward.  The correction can be as simple as saying NO in a dominant voice every time she bites.  Other ways to correct include:
1. holding her mouth closed until she squeals.
2. Scuffing her for 10 seconds or until she squeals.
3. Placing her on her back for a count of 10 seconds.
4. Shaking a can containing pebbles as a noise deterrent.  
5. Blasting an air horn in her face.
6. Giving a time out (Put her in a place with no human or other distractions for 5 minutes).
7. Biting her back on her nose  (just enough to let her know that you mean business but not hard enough to break skin).

Any correction must be done while the behavior is occurring or directly after, and it must be done EVERY TIME she bites.  Do not allow her to get away with biting ever!   At first she may not stop immediately after the correction, but this will change over time as she learns.  Once she immediately stops biting she should be rewarded by pats, petting, praise, and food treats when she is really good.  This will become an important job for you for awhile.  Consistency is extremely important!  She should never get away with bad behavior, ever!

I don't know which correction will be best for her, but the correction that most dominant dogs hate the most is being forced unto their backs since this is a very submissive posture, but it will show her that her place in the pack is below alpha.
Good luck!