I usually raise ducklings but right now I am brooding 10 chicks, one guinea keet, and four ducklings together for the first time. It's working out pretty well so far. I brood them outside and the weather is between 90 and 100° during the day. I could have the ducklings off of heat right now and they'd be fine, but I'm not so sure about the chicks and the guinea since I don't have as much experience with them. The ducklings are one and two weeks old, the chicks and the keet are one week old. How old do they need to be to have the heat off completely?