I really dont want to have a lot of kids at my wedding, just the ones that are part of my family or my fiancees family. There really arent that many, probably 5 altogether, and i like that. How do i keep from having other guests bring their kids, especially if me and my fiancee dont want them there? I just dont want them messing things up and getting into trouble, because i know some parents dont look after their kids that well at these types of events, they just let them run of and do whatever they want. I want a polite way to tell guests that this is basically an adult only wedding. Any suggestions?

Here are a couple ideas:
You can indicate it on your reception card for an adult only reception
or
You can put a note in the wedding invitation stating:
"please let us know if you need to arrange childcare on the night of the
wedding and we will be happy to give you some references".
Hope this helps!!
Krista-
Wedding, Bridal & Baby Shower Table Cards, Place Cards, Favor Tags, Note Cards, and Programs

Indicate in your invitation that it is a adult reception.

On the response card, put "_________ # of adults attending."

On the wedding invitation, you write, " Mr and Mrs Miller."
That way it is only directed to the parents. If you were to write, Mr and Mrs Miller, and family, that would mean bring the kids.

With my fiancee and I, we only have 3 children at and in our wedding. We are specifying that this is an adult affair only. To me, if you tell people adult reception they will probably bring their children to the ceremony and then either leave and go home or leave and take them home and have to come back and 9 times out of 10 they won't come back. That's why we are choosing to say adult affair only. Just our opinion.