I had 13 hens setting at one time a couple months ago, out of the hens I have 11 chicks hatch. I've hatched 3 incubators full until last week my newest bator had the fan quit right at time me of lock down, 9 died 2 failed to hatch and 8 are still doing great. I'll take a incubator over a hen, oh and I had one hen kill her chicks. Brinsea use to make a Octagon that is one of the best incubators I've used, their new model is a Ovation. I definitely do not like it, it's a little over a year old and it's had 2 new fans.