They finally got to go outside for about an hour. For the first 10 minutes they just stood there looking at the grass and listening to the outdoor sounds. They seem really confused. Then they started to walk around a bit, scratching and picking. A couple of them started trying to fly, jumping and flapping their wings. I'll keep doing this until they are a bit older. I think they enjoyed it.
Nice lawn too, the grass here is more or less dead and hasn't started to regrow yet. 
