Chicken eggs get a humidity increase on day 18. In summer I had an early hatch on days 18 and 19. I believe it's because everything was running a little too warm.
It's an incubator, but it was designed to also be used as a warming dome or brooder if desired. There were separate sections you could purchase to make it taller or create doorways but they're discontinued.
I'm late to the hatchalong, but I'll be going back to the beginning to see what I've missed.
I have eggs under broodies, but tomorrow is day 18 for one of them and I'll be candling and taking some out to place in a hatcher. I'm a little anxious about doing this but she's sitting on eggs from...