They will stay together in a small group and wander about. No they will not fly away. They can fit through some amazingly small holes. I used a box to transport them outside then would leave the box on it's side in the pen.The first time they were hesitant to leave the box. It offer a place of security. The first few trips out they would return to the box when they were ready to go in. Later I had to herd them into the box to return them to the brooder as they didn't want to come back in anymore. If one or two are hesitant to come back in get as many as you can back in the brooder, the straggler will realize he is alone and want back with their buddies asap.