Where do you live exactly? If it is Johnson Lane you might have snakes, spiders, hornets, wasps, and maybe bats. Most of the others, coyotes, rabbits, squires, mice and vowels will do their very best to stay away from you and your kids.
In the forested areas you can find raccoons, bobcats, deer, cougars and even bears. Again ... most of them would just as soon leave you alone as mess with you but, it's definitely a good idea to keep little kids under a watchful eye. The biggest problem is small animals like little dogs and cats .. coyotes will get them and that can happen in very populated areas, I live on Centerville Rd and Waterloo and we have had coyotes at our back fence. I don't let my little dogs out alone.
Also, we have had hawks get our chickens and go after our small dogs. No danger to your kids of course but do mind your pets.