Family is what got me started in photography. Whether your kids are humans or animals (or humans behaving like animals) I make sure that we not only create great photos but have fun at the same time. Don't worry about the little ones, I'm in charge of the kids, they won't listen to you anyway! I have plenty of experience getting genuine expressions out of the kiddos, so just leave it up to me.
We move around, explore, & play to bring out those genuine expressions. What you wont see is anyone yelling at the kids or stressing out about not sitting still.