How did you decide on age groups?

Sometimes you find out what age group is best AFTER you have each age group lol, and then many will say it isn't about age, but the individual. I only agree with that to a point though. I would never do teens b/c I have younger kids, as well as two teens myself. We have found that we really like the baby/infant stage. Any child older than that causes more arguing,fighting,competition,jealousy etc, and my bios don't need extra partner in crimes in that area. :evilgrin: