@Natashia1 Many people are under the impression that kids are free.
You have to be EXPLICIT in your advertising. My house rules and my communication with the guest states that the property may be occupied by X number of guests, INCLUDING infants and children. This is per local zoning ordinances and licensure.
Zoning does not differentiate between adults, infants and children. The property is permitted X number of human beings, based on square footage, number of bedrooms and number of bathrooms. If the guest registers a bunch of "infants" I will tell them that I cannot accommodate that number of human beings and I will ask them to cancel their booking.