I let them all into the cage at night. At about a quarter to 7pm they are chattering away, waiting for me to open the door so they can get all settled in. Then I cover the cage so they are all 'tucked' in. They do have good air circulation though. I have a little wood ramp that I put up to the door but in the evening they don't even wait for me to put it in place, they just fly up to the open door! Then at daybreak I go out and let them out to the run area.