We do not include kids. Its a nice offset to the family-oriented block parties. We have a deck crawl in the fall when we can enjoy fire pits and cooler weather. If schedules permit, summertime is great though. No more than eight families are needed to host. That's 30 min per deck/patio and 4 hours. 5 to 6 decks is ideal. Each year there is a theme and couples buy tickets to defray liquor cost. Host couples do not buy tix. The theme might be "sports". So the host couple wears basketball jerseys and serves beer and nachos, for example. The next home may be football and the host couple wears football team jerseys and has a tailgate type drink/snack....and so on. Visiting couples may also dress up in sports attire.
One year we did different countries: Mexico, Italy, Ireland, USA, France with drinks/ cheeses from each country. It's a great way to loosen up with neighbors and checkout their landscaping, that you may not otherwise get to see.