From Egg to Chicken (Pt 3) Humidity and day 18

In part 3 of this series, we look at 2 important points, humidity and day 18.
I'm always being asked about humidity, as this is important when incubating eggs. You need to get it right, but its not as hard as many people may make out.
The next important part is day 18, when the eggs are placed into lockdown, and are getting ready for the hatch.