I have a 16 month old that knows no boundries. I also have his 3.5 yr old brother. they like to rough house and so now the younger one climbs on the other kids takes anything he wants, and he wants everything that every one else has. he breaks up puzzles that the older ones are doing , knocks over lego creations, ect. soooooo I have a play yard (6 sides and no bottom) that I use when this child is having a hard time remembering his manners. but sometimes I put the older kids in it to do their puzzle or build their lego castle and they think its fun....sometimes I put a blanket over it and they go in there with flashlights .....I found mine on kijiji for about 40 bucks.