Ive had this happen before; it has to do with the humidity levels not being right inside the bator. It's not a worry unless it prevents them from staying warm. That fluff is what helps them stay warm, kind of like a nice fluffy sweater or jacket helps us stay warm.
You can do a few things. First is what has already been suggested.
Second, if they are acting fussy, like they're not as warm as they'd like, is you can give them a sponge bath with hot water - it has to be warmer than our body temp, as a chicken's body temperature us normally 104° - 109° F (about 40° to 42 1/2° C). Sponge their back with a damp but not dripping wet sponge, going against the "grain" of the fluff, and gently "scrub" a bit. Then immediately put thrm back under the heat source, so they can dry off and stay warm while they do.
Or, third, if they don't seem to be bothered by it, and are staying warm, and not being picked at by the other little ones, you can just let them be. It will slough off and go away on its own in a few days, no harm done.
You can do a few things. First is what has already been suggested.
Second, if they are acting fussy, like they're not as warm as they'd like, is you can give them a sponge bath with hot water - it has to be warmer than our body temp, as a chicken's body temperature us normally 104° - 109° F (about 40° to 42 1/2° C). Sponge their back with a damp but not dripping wet sponge, going against the "grain" of the fluff, and gently "scrub" a bit. Then immediately put thrm back under the heat source, so they can dry off and stay warm while they do.
Or, third, if they don't seem to be bothered by it, and are staying warm, and not being picked at by the other little ones, you can just let them be. It will slough off and go away on its own in a few days, no harm done.
