Sibling Rivalry

My children seem to be always screaming about something.

"He caled me weirdo!"
"Get your feet out of my face!"
"You are so annoying!"
"He's copying me!"
"Get off me!"
"I can't breathe!"
"I'm telling!"

On the other hand, they get mad when they are they only ones at home, when no one will go with them in the car someplace, when the other kids get in trouble, and when one has baseball practice and the other does not.

They completely love each other and they completely annoy each other.

Does anyone else have this same problem?