Is there always an alpha female and alpha male in a household? What are some of the behaviors??

I am curious because it seems that with our five - 3 males and 2 females - there is nobody who seems to be boss at all. Both girls are very easy going and sweet - maybe Emily is a bit more testy and she does have small tantrums now and then, but not towards Lizzie.

The boys - well Dylan is the biggest but is usually so gentle and moves aside most of the time. Like Emily - he has a temper when he has had enough - but seldom shows it.

So - do some households just not have alphas??

Since Boomer is coming to us as an adult male - are there likely to be more territory issues with him? Does the newcomer ever become the alpha? Will his coming be likely to make one of the others want to be bossman??

Thanks!!