Relative Humidity (RH) in the hatcher at the end of the incubation process will be high (approx. 80%). Houses with whole-house heating, especially where nipple drinkers are used, can have RH levels lower than 25%. Houses with more conventional equipment (such as spot brooders, which produce moisture as a by-product of combustion, and bell drinkers, which have open water surfaces) have a much higher RH, usually over 50%. To limit the shock to the chicks when transferring from the incubator, RH levels in the first 3 days after placement should be 60-70%. Chicks kept at the correct humidity levels are less prone to dehydration and generally make a better, more uniform start.