Fighting Budgies

Question
I've had 2 young budgies for about a month and a half now.  Their ceres are still white so I know they're under 4 months of age, I'm not sure of their genders.  When I first got them, they bonded almost immediatley, and were preening each other's feathers and regurgitating for each other.  Now for the past few days, they've been fighting (chattering, pecking, and chasing each other around the cage) and bullying each other from the food, water, perches, and toys.  I have 2 of each food and water bowls so one doesn't go hungry/thirsty but I'm wondering if this will pass.  What confuses me is they still are affectionate with each other, they still regurgitate and preen each other.  They're not getting injured but I'm wondering if they'll be happier in a different situation.   

I'm also considering buying one or 2 more budgies, and housing the new ones with the ones I have now in a brand new larger cage.  I understand there might be territorial issues if I put the new ones in the cage I use currently and I think they'd all be happier in a larger cage.  Is it wise to combine a bonded couple with 2 new parakeets?  

Answer
Hello Celine! It sounds like two little kids! (laughs) In the wild budgies live in flocks and sometimes need to assert their dominance over one another. This fighting is normal. Females will fight other females for nesting sights, males will fight over females, and males and females can be very competitive with territory. Its normal to worry about them getting hurt but this is their way of comunicating with each other. If the cage is small, they may have territory issues. You know they dont hate each other if they feed and preen. If your buying 2 more keets, throw em' all in the same cage! The more parakeets the better. They are flock animals and enjoy being in numbers. The other 2 you have shouldnt have a problem in a new cage, it actully may solve the problem. Parakeets are gentle birds overal so having two more wont cause major problems. Good luck!