You may send the child to a different page, allow the child a drop down menu of birthdates for all ages or even ask the child to enter a birthdate. Once you have determined the child is under 13, you must acquire verified parental consent before you can collect any other data from that child. Websites that are targeted to adults fall under the Rule once they have actual knowledge the child is under 13. Well, it depends. Recent demographic studies have shown a high percentage of the audience between the ages of 6 and 17 on several sites I personally thought that children would not be interested in.
Different circumstances require different ways of dealing with the information.
However, for an online community kid site, this may not be practical. Take a look at the frequently asked questions and the information available to you on the FTC's website. We've broken the questions down into sections for easier access. Feel free to print these for reference. All attendees were encouraged to check the FTC's website regularly for information and updates and to take advantage of the educational material available.