More about cocker puppy aggression

Question
I would like to also ask about my male cocker spaniel puppies biting but at 14 weeks, he is also showing his teeth to most anyone except our family and has tried to nip at a 3 year old child.  He acts almost like he's terrified of anyone but us.  He has only been with us for 1 1/2 weeks now but I'm confused as to why he would be acting this way.  He will also scream if approached by stranger's.  What does this mean???  What can I do to address and control the issues???   Thank you.

Answer
Huuuuuuuuuuuum, what did I say in my first answer?  No easy way to look back until I answer this question.  Excuse me if I repeat.  

The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/

As top dog, you should be trusted to protect him from nasty strangers.  Part of the problem is he may not have been exposed to enough stranger before 12 weeks. It may be extra tough.  This is one of the few cases where I suggest treats.  You can give them to people he doesn't know.  Treats don't have to be fancy, a little of his regular kibble will do.  

Here are some more gentle ways to exert yourself as top dog:

''Elevation for small puppies:  Sit on the floor and gently put your hands around your pup's middle, below his front legs, and lift him up.  He is facing you.  Hold him for 15 seconds.  Repeat until he no longer struggles.  If he is past 10-12 weeks, lift his front feet off the ground, but don't pick him up.  

Cradling for small puppies:  Hold your puppy gently on his back, as you would cradle a small baby.  If he struggles, hold him firmly until he quiets for 10-15 seconds.  With larger pups, you can do this as your sit on the floor, with your pup between your legs.

Quiet lying down:  Place your pup on the floor on his side, with all 4 legs pointing away from you.  Use your hands on his neck/shoulder area and middle, to hold him in this position.  When he is quiet, praise him.  Lengthen the time that you keep him quietly in this position.  When he accepts this position well, handle his paws and muzzle, while keeping him quiet.''

The quotes mean this isn't my original work.  It is copied from my Puppy Raising Manual.  I have long used these or minor variations of them, and they are very effective.  You may want to give him a belly rub while he is on his back too.  Helps bonding.  There is a big difference between him rolling over and demanding a belly rub, and you choosing a time to roll him over and rub his belly.  The latter cements your place as pack leader.