Incubating Chicken Eggs – Day 18 Through the Hatching Process

This is the 3rd and final post in our Incubating Chicken Eggs Series.  Read the first two posts by clicking the following links:

How to Prepare for an Incubation

Incubating Chicken Eggs – the First 17 Days

Once you have candled on day 17 and removed any obvious dead eggs you prepare for “Lock-Down.”  You need to remove the egg turner (if you have one) and set all the eggs on their sides flat on the bottom of the incubator.  You also need to raise the incubator humidity up to about 65-75% (lower for high altitude).  During the days that follow you need to open the incubator as little as possible, only when absolutely necessary to maintain the humidity (thus the term “lock-down”).  If the water reservoirs in your incubator are not enough to keep the humidity up you can add wet paper towels to the incubator.  I ball them up loosely and then put them in and pour water on them.  I continue to wet them as needed.  Do not use small containers of water because your chicks could drown in them after hatch if you aren’t careful.

Now you wait in excited anticipation for the hatch to begin!  Keep the humidity up while you wait and through the entire hatch.  The first chick can pip anywhere from day 20-24ish, but most hatches take place on day 21.  It can take about 24-72 hours for the hatch to complete (from the first chick to the last chick).

Let’s look at the hatching process.  This is a repost from my blog a few years ago…


The Hatching Process

I always thought that a chick just hatched.  It just busted out of the egg in a big spurt of energy.  Like one minute inside the egg, the next minute broken egg with chick out.  Silly I guess, but true.  It has been fun to learn about how a chick hatches, and especially to watch it first-hand.

Here is how a chick hatches:

1.  Internal Pip – the internal pip is when the chick uses it’s beak to break through the membrane into the air cell in the fat end of the egg.  It will take its first breath and start breathing regularly and even cheeping once this happens.  You can’t see anything from outside the egg, but you can hear it cheeping from inside the egg.  The egg often wobbles around a lot too during this time as the chick wiggles.

2.  External Pip – the external pip is when the chick uses its beak to break through the shell, leaving one little crack or hole.  This happens after it has already broken into the air cell and started breathing.  As you can see in the pictures, sometimes a pip is actually a hole and the shell falls off there, sometimes it is just a few cracks in the shell and it sticks out a bit.

photo 10Sometimes, as in the second picture above, the chick does not get into proper position inside the egg to perform an internal pip into the air cell first.  It is called a mal-positioned chick and it performs a mal-positioned external pip, and no internal pip.  A mal-positioned pip usually takes longer to get out because it is just taking its first breaths at the time of the external pip and thus is combining the time for internal and external into one time.  Sometimes, they don’t survive at all.

3.  After the external pip there is often a long period of time with little to no activity with the egg.  If the pip is a hole you can see the beak inside the hole moving a bit, opening and closing, and cheeping occasionally.  During this time the chick is absorbing all the blood from the vessels in the membrane of the shell, as well as absorbing the yolk into its abdomen.  This is why chicks don’t need to eat right away, because they have the energy from the yolk to live on.

4.  Zip (or unzip) – Once the chick has absorbed everything it needs to absorb it will start to “unzip” its shell.  It makes a line of pips about 3/4 of the way to almost all the way around the egg, creating kind of a cap.  Here are some examples of zips.

h1 h2.5 h25. Kick and Hatch – when the chick has finished unzipping the shell it begins to kick its feet and push with its head over and over again, slowly (or fast, depending on the chick) breaking off the cap and getting out of the shell.  The chick in the pictures below actually got its toes out the crack a bit during kicking.

h3 h4 h5 h6 h7 h8 h10When the chick comes out it is wet and pretty tired.  Most of them lay around for a bit, but some get right to the business of learning to walk.

The time frame on all the above steps varies SO much between chicks.  Our two quickest chicks went from pip to hatch in only 3 and 4 hours.  Our two longest, both mal-positioned pips, took 24 and 27 hours.  Most of the chicks went from external pip to hatch in about 12-14 hours.

It is such an amazing process and our family has enjoyed watching it SO much.  It never got boring, even by the 23rd hatch we still came running when someone yelled “chick hatching!”


When the chicks start hatching and learning to walk they will be jostling the other eggs as they scramble around the incubator.  We have found that it is best to leave them in the incubator until they are fully dry, even though they are jostling the other eggs.  Sometimes we use one of our incubators for hatching and the other for drying, this decreases the jostling.

Once a chick is fully dry we open it quickly and get them out and put them in the brooder.  We go quickly so as not to let too much humidity out since it is important for the hatching ones to still have plenty of humidity.

We have now discussed the entire incubating and hatching process!  I hope you get the chance to enjoy watching this miracle in action at some point.

7 thoughts on “Incubating Chicken Eggs – Day 18 Through the Hatching Process

  1. Very interesting to see.
    I am facing a problem. My chicks are not getting out of the egg and dies. What is the reason?
    My process parameters: Temp is 100to 102F, Humidity: 70 to 80% for 1st 17 days. Later it’s 85 to 90%
    My yield is hardly 20%.
    Machine is fully automatic egg incubator for hatching 48chicken eggs.

    Liked by 1 person

  2. Optimum temperature is 99.5F/37.5C. Temperatures above 104F are fatal, anything above 102.5 and I’ll let the eggs cool for 15 minutes and possibly adjust the temperature on the incubator.

    An infrared thermometer will give you the actual egg temperature, which may be higher than incubator air temperature close to hatching. Try to avoid getting one with a built in laser pointer.

    I usually drop my temp to 98.6 during lockdown. The chick works hard during hatching and development should be close to finished so the lower temp keeps the chick from getting exhausted. Imaging working out in a sauna with a fever for hours and you can see why you need to make sure temperature and humidity are right.

    My humidity varies between 45 to 65 and I adjust it based on how much weight the eggs are losing and how well the air cell is developing. Close to hatching I adjust humidity to about 75, but if the air cell hasn’t developed well high humidity may mean the chick drowns in the shell so candle on day 18 to make sure you actually need the higher humidity. If all is going as it should the higher humidity keeps the inner membrane from drying out which would fatally limit the chicks’ mobility. Either way you’ll want to drop the temperature a bit on day 20 or 21.


  3. Hi! This is my first go around. I am on day 18.. when I take the plastic turner out of my incubator and set the eggs on their side, should I turn them myself 3-5 times a day or leave them alone these final 3 days?

    Liked by 1 person

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