I see this question on the forum a lot and after my experience, I have to say: it's not a problem with the kids, it's parents. GET READY FOR A RANT.
In my wedding we graciously allowed the grooms side 50 guests, which they ballooned up to ~90 (this is a totally different issue) because they invited everyone with their little kids. On my side, we were very picky with our invitations and most cases, except for family, was Mr. & Mrs. only. Now, there are definitely some obnoxious guests who bullied their way into bringing all 3 of their kids anyway.
OK. So my low-to-no kids wedding was now full of kids. I took the hit and rolled with the punches. You know what? I'm getting married and nothing's going to change that it's a happy day. I don't mind kids, they're guests and will enjoy. If their parents want to bring them, fine.
Unfortunately, I did not realize that these parents were straight up ridiculous. Bringing your kids to a wedding is not an excuse to say "oh, there are 200+ other adults who will watch my kids while I enjoy the wedding and mingle." You do not let your kids run wild. I would be mortified if my child went up to the stage reserved for the bride and groom and sat there for an hour.
My stage had kids in my seat the whole night. Not one or two kids, at least 6-7. I have to get this off my chest guys: these kids and their parents were SNOTS.
My venue was stunning and lush which gigantic 20 foot crystal chandeliers--it is incredibly upscale. While we were taking pictures I watched a 5 year old girl wander around unsupervised. She threw a favor bag up into the chandelier, it shook around a bit, and then the bag was stuck there for the rest of the night. This could have been a huge accident. I watched my event manager's face turn to stone, and bless his heart he went straight to the parents.
It is mind-boggling to me how parents can be so lackadaisical about this. Look, I know it's your angel, but we ain't paying $20K for a replacement chandelier because of that angel. And my photographers are not here to document how great your kids look in the bride and groom seats, and no one except your family wants pictures with your kids. These kids wouldn't even move for pictures--they are literally in most of my pictures because no one, including the parents, had the backbone to move them. No one thinks it's cute that you can't handle them. My photographer is a dear and had them cropped out wherever possible. But come on, this shouldn't even be an issue!
I know this turned into a giant rant LOL but I wanted to warn you guys: kids or no kids is not the issue--kids will always be kids no matter what. You can't discipline a baby for crying. It's the parents. Are they capable and willing to watch their kids the whole night? Do you trust them? There was no way for me know that some parents don't care what their kids are doing. Learn from my mistake: if you are inviting children, delegate someone to be firm enough to call parents' attention to the disruption their kids are causing.
This was not something that I as a bride was in a position to handle--the whole day I'm focused on letting things be and enjoying, but now I do regret how many family photos I have with someone else's kids. These were supposed to be photos with my sister, my parents, etc. and there's the kid who no one could move in the corner.
Parents--PLEASE keep an eye on your kids! I don't mind "reasonable" things like crying, I understand there isn't much you can do, but they shouldn't be running around disrupting other guests, much less the bride and groom! And they shouldn't be causing damage!