That is not to say we have not had our struggles. From about 12 months to 30 months our family sits in the back of the church, allowing for a quick departure for rambunctious toddlers and Wingnut. During this period of growth and maturity, out children spend most of their Mass in the vestibule with their father working on better Mass behavior.
Our standards are fairly clear, they are expected to sit quietly next to Daddy or in his lap. They are not allowed to fiddle around with the hymnals or missals. They are expected to sit, stand, or kneel(or be held by Dad) when the rest of the parish sits, stands or kneels. Good behavior is rewarded, usually with donuts or Rita's Ice, or some other treat. Bad behavior is punished. The culprit is relegated to watching the rest of his siblings eating donuts or Rita's Ice, or some other treat.
Obviously this program is not for everyone, but for our family it works and works very well. Baby Wingnut, along with the rest of the family, is now sitting at the front of the church during Mass and very rarely needs to exit to the vestibule. We spend our Sunday mornings talking about how he's going to behave at Mass and what kind of treat he will get if he is a "good boy" at Mass. Since Christmas, I can recall only a single time Baby Wingnut has not earned a reward. As time goes on, rewards will no longer be needed. Good behavior will just be a matter of course.
This past Sunday I had the following exchange with Baby Wingnut just before leaving for Mass:
BW: "I'm going to be awesome at Mass today."
Me: "Yes, you are. That's what good boys do."
BW: "Yep, I won't run and I won't tackle."
Evidently his standards of conduct do not quite match ours, but we are working on that.
As a little side story, Elizabeth Foss has recently written a sweet article about the same subject here.