You have quite a few dogs at that teenager stage, they may be starting to challenge eachother for dominance.

this is a difficult behavior to change. I would keep sternly disciplining them.
Also make sure they are getting enough excersize (tired dogs = a calm house lol) and make sure they have stimulationg toys (kongs & buster cubes etc...)

Try to determain who is where in their pack (alpha and so on) and treat them by pecking order as well (feed them in order, let them outside in order etc..) Althpough this may be tough at their age as like i said before they are at that age when they want to be the dominant one.

I would speek w/ a behavorist if it causing problems & you can not control it.