I had about 30 chicks in the house 10 where 2 weeks older then the other 20. But we had them in hte house for about a month and a half. when it was just 10 i changed their bedding every ohter day when we moved to 30 in total i changed it everyday. the smell was not bad till the older ones turned a month old then they got to smellin. and then went out in the coop with heat lap.