Two 5 month old puppies

Question
I have 2 questions.  I have 2 female bulldog puppy sisters.  They are no longer sleeping in their kennels and sleep out on dog beds.  Lately, they have been peeing on their beds.  Everytime I come home I see a pee spot.  Why are they doing this and how can I make them stop.  

2. Is there a way to stop toy and bone aggression between the two.  Most of the time they are fine and they will play and chew on bones together.  Every now and again they will get aggressive and fight.  When this happens I make a loud noise and they stop and I take away their bones.  Is there something else I can do to make this stop.  I don't want this to become more of an issue as they get to be adults.  

Thanks

Answer
1 It could be a UTI, have the vet check them.  It really sounds like a who is in charge issue.  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/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm  You may need to spay them soon.

2  That sound normal or even less aggressive than normal.  Of course Labs tend to be a bunch of ruffians and Shepherds even worse.  The real difference I see is the bulk of the time they are going at each other with bothering with a bone or chew.