VERY high humidity when hatching?

[joe17]

I usually keep my humidity around 70% when hatching eggs. When a chick hatches, the humidity goes up by 10%!! Too high humidity can cause some chicks to drown and not hatch. Should I be worried about this every time a chick hatches??

 

[eggsited chickens]

If mine got above70% I would just open one of the vents, and that was good enough to let some of the humidity out.

 

[loopy12]

Mine does the same as soon as a chick hatches but it settles back down within 20 minutes or so, so I leave it. If I get 4 or 5 popping out at once, or when there are alot already hatched then it goes up and stays up and then I open a vent for a bit.
Drowning with high humidity is an issue but I also find that after pipping the membranes get really stretchy if humidity is too high and the chicks can't turn to zip and eventually die, presumably from exhaustion

I try to keep it at 65% for chicks, 70% for ducklings, no more than 5% higher.