A mother hen seems to know instinctively what her eggs need. If it’s very hot,
she gets off the eggs to let them cool a little; if it’s cold, she sits tightly. Her
body provides the perfect humidity, and she fills it with water herself. When
you take over the job of incubation, you can never be as good as a hen, but,
with careful attention to details, you can have a successful hatch from an
Hens don’t actually turn their eggs with their beaks on a regular basis as
many people think. (They do occasionally rearrange them with their beaks,
but it’s usually for their own comfort.) Instead, their coming and going from
the nest and shifting positions to get comfortable alter the position of the egg
several times a day.
There’s some debate about turning eggs, but most experts believe the position
of eggs should be changed two or three times a day for the first 18 days
of incubation. Automatic egg turners can do this for you, or you can do it
yourself by rolling the eggs to a new position. The turning keeps the embryo
from becoming attached to the outer membranes and the eggshell. If you’re
turning the eggs yourself, do it quickly so you don’t chill the eggs too much.
If you have egg racks for turning eggs in your incubator, place the eggs in the
racks with the small end down. If you’re using an incubator without racks, lay
the eggs on their sides. Cluster them in the center of the incubator if there’s
lots of room.
Wash your hands before handling eggs. Oil or bacteria from your hands
can cause hatching problems. Warm hands are much friendlier to eggs than
cold ones. (How do you feel when someone touches you suddenly with cold
hands?) And be sure to wash your hands again after touching the eggs.
On the 18th day, stop turning the eggs. If you’re using an automatic egg
turner, be sure to turn it off. The chicks are getting in position to hatch, and
they don’t have much room to move around anyway. If you change the position
of the eggs at this point, the chicks have to reposition themselves for
hatching, and doing so wastes valuable energy and may even make it impossible
for them to hatch.