In almost every wedding Kids are not allow to be in the Reception. Some kids are allow to be in the Ceremony and the cocktail hour, but no in the reception time. In some cases the couples hired an entertainment or sitters just for the kids, on a separate room.
The reasons varies in each event but, when is alcohol involve is better to have just adults. One of the reason is because sometimes the kids are running around the dance floor and touching everything they are not supposed to be touching. No every wedding is only family members and sometimes the kids got bored because they don't have nothing to do or someone to play with, than the parents have to leave the party early.
But I believe one of the mayor reason the couples don't want any kids in their wedding reception is the food cost, remember every guess is money they have to pay to the caterer or banquet hall. If the kids are to little and don't eat the regular food menu you are serving, you have to order a different menu just for the kids. Usually kids under 2 years old don't pay for food. Sometimes the kids don't event touch the food and that is a money that goes straight to the trash.
What do you think? Kids or no Kids in the reception?