Incubation - Day 21.

It's here - we've done it - it's hatch day!

All our hard work for the past 20 days of incubation is about to pay off as our egglets begin to hatch.

But a word of warning and of advice : not all eggs hatch at Day 21!  It's most common today but if your eggs are showing no signs of pipping yet please, do not worry.

Read on for more information.

What's going on in the egg today?

The yolk sac together with its blood supply is now fully absorbed into the chick and will provide nourishment for the first critical few days after hatching. 

The 'umbilicus' or belly button closes over; when the chick has hatched you might see the stalk still attached - it looks like a dark piece of cotton and it will drop off within a couple of days.

Now the chick is ready to hatch.

What's happening to the chick at day 21 of incubation?

Between Days 20 and 21 the chick's neck begins to spasm and it 'pips' or breaks through the internal membrane and takes its first breath from the air cell. 

This is a critical point in terms of humidity : dry air would mean the membrane would literally shrink round the chick and it would not be able to hatch.

The incubated egg at day 21.

An artist's impression of a chicken egg at the 21st day of incubation.

Within the next few hours the chick will need more oxygen than the air cell can give and will use the egg tooth to break through the shell's outer membrane, and then the shell itself. 

That's the first sign we'll be able to see that the process of hatching has begun.

Chicken egg pipping at day 21 of incubation

And once again, we need to have patience! 

From first pip to hatch does not happen immediately - incubation has been a peaceful process but hatching is a tiring business and the chick needs to rest!

Some will hatch very quickly but I've had a chick pip and show no further signs of development at all for 21 hours.

As long as the chick has this small breathing hole, and given that you're keeping humidity levels raised to around 65%, it really doesn't matter that it's not gone any further straight away.

Don't worry and above all, don't be tempted to "help" at this point.

What's the next stage?

The next stage is commonly called "unzipping".

The chick uses its wing as a guide and its legs to propel turning.  With the hard, pointed egg tooth it pecks through the shell in a roughly circular motion until almost the whole of the blunt end of the shell has been pecked through.

These next pics are of one of my Wyandotte chicks hatching; it took 25 hours from first pip to hatch.  She is now a healthy, happy adult chicken.

A chick partway through hatching from its egg at day 21 of incubation.

At that point the chick's legs take on a lot of the work.  They push the two halves of the shell apart ...

A Wyandotte chick part way through hatching.

... until the chick is finally able to push and pull its way free.

A Wyandotte chick in the final stage of hatching.

Hatch is complete.

What happens now?

The chick should be left in the incubator until it's dried out and fluffed up.   Be careful here - chicks can chill very easily and you should not move them too soon.

The newly hatched chick will very quickly find its feet and then proceed to stumble around the incubator, bumping into, lying on and climbing over other eggs and newly hatched chicks.

Newly hatched chicks will often spend time lying on top of other eggs even as they're hatching!

Two newly hatched chicks rest on top of other eggs

When I first experienced this I wanted to "save" the other eggs by moving those who had hatched.

I later learned that the cheeping and bumping of the newly hatched is thought to be a motivation for the unhatched chicks to start pipping.

When is it safe to move the chicks to their brooder?

They should be completely dried out and fluffy before they go anywhere.

However, sometimes it's difficult for them to dry out if other chicks are hatching and humidity is very high.

I'm lucky enough to have a separate incubator which I keep at the ready to put newly-hatched chicks in if they're having a hard time fluffing up. I bought it after having lost a chick who had hatched successfully but who couldn't dry properly and was chilled.

I was devastated - and despite it costing money I vowed never to be in that position again.  So I bought a second Brinsea Mini Advance - my favourite of all incubators.

Newly hatched chicks drying in the incubator.

However, I do not move them from their original incubator until I'm certain that no other eggs have pipped.  Lifting the incubator lid at that point could cause the membrane of the unhatched chicks to dry out and prevent a successful hatch.

Anything else should we be doing today?

As this process begins, you may be able to hear sounds of the chick 'peeping' before you see even a tiny hole in the shell.  In natural circumstances the mother hen will cluck to her eggs to encourage them to hatch, and the chick will cheep back.

Have I ever tried to be a 'mother hen' and cluck to my eggs? 

Of course! 

Can anything go wrong at this stage?

The major problem  on hatch day is that we try to assist hatch before the chick is ready.

I have more e-mails from people worried that their chicks are not hatching precisely at Day 21 than on any other subject.

Close up of an egg tooth as a chick hatches.

Chicks are not machines!  Although the stages of incubation are the same for all eggs the time it takes to complete them is not, necessarily.  I've had chicks hatch at Day 19 and others at Day 24.

Don't be tempted to "help" your chicks out of their shells - please!  If they're not pipping or they've pipped but they're not unzipping, they're not ready.

If the yolk sac together with the blood vessels have not been fully absorbed into the stomach, the likelihood is that trying to 'help' by peeling away the shell will rupture one of these blood vessels and the chick will bleed to death.

Remember - from pip to hatch can take as long as 36 hours.  It's a tiring process for a little chick!

Question of the day.

When would the time be right for me to assist a chick out of the egg?

The answer to this is - virtually never.

In fact some people would say categorically "never".  There's a view that a chick which isn't able to hatch on its own will be too weak to survive anyway.

I don't hold to that view - I do think there's a time to help, but it's rarely as soon as you think it is.

To some extent this is a judgement call which comes with experience.  If the chick has pipped through the shell but there has been no further development for 12 hours or more, it may be possible to help.

But it needs to be done carefully and patiently. 

Here are some pages related to today's issues.

In case you've missed them, these pages relate to different stages of incubation which have a bearing on today's hatch.

Click on any of the pics to go to that page.

Development of the egg tooth.

Why assisted hatching can kill.

More about assisted hatching.

Incubation day 7, including how the egg tooth develops.
Day 11 of incubation, including why assisted hatching is a bad idea.
Incubation day 18, including further information on assisted hatching.

Other pages you may find helpful.

The first link is to a general overview of days 20 and 21 of incubation.  It's nothing like as detailed as this series but a good place to start if you need a less comprehensive view.

Click on any of these images to go to that page.

An overview of days 20 and 21 in the incubation process.
10 steps to choosing the perfect egg incubator for you.
Have questions about hatching? You may find the answers at this link.

Would you like a reminder e-mail at each day of the incubation process?

Link to my 28 day guide to incubating and hatching chicken eggs.

If you want e-mails personally delivered every day of incubation with a link to my pages telling you exactly what's going on during each step of the incubation process, you need to sign up for my series called "Hatching Happy Chickens". 

If it sounds interesting to you and you'd like to know more, the image to the left is a link to details about  exactly what you'll get.

Looking forward, looking back!

The easiest way to follow my hatching series is to sign up for the e-mails.  However, if you'd rather not do that, these are links you need to work logically through the series.




Link to my 28 day guide to incubating and hatching chicken eggs.
Go back to yesterday's incubation page.

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