How to Hatch Eggs

Hatching eggs can be a very rewarding experience and many beginners are buying incubators since they have become far more affordable over the last few years. The main manufacturers for the hobby market seem to be R-COM and Brinsea Incubators and both produce an excellent range that can accommodate 20 to 25 chicken eggs, perfect for the beginner to hatch their own eggs!

Before you start

Before you incubate and hatch chicks, you should remember that you will end up with a ratio of half male and half female chicks. Unless you are hatching an autosexing breed (where markings or colour of the chicks are different colours) or have crossed two birds that give a sex-linked chick (again, different down colour or markings) then you will need to think ahead  to when the young growers can be sexed around 8 weeks of age and consider what you will do with the excess of male birds. Sadly, they are very hard to re-home, everyone has the same problem: too many boys.

Choice of incubator

incubator

The R-Com Suro is a forced air incubator that controls both temperature and humidity.

There are essentially two types of incubator –still air and forced air. The big difference between the two is the forced air uses a fan which circulates the air inside. When you measure the temperature, it should be the same throughout. The still air incubator has a temperature gradient inside so the hotter air rises to the top and there can be several degrees difference between top and bottom. For the average beginner wanting to increase the size of their flock, a forced air incubator is in my opinion the best choice. If you can afford a model that has automatic humidity control then you should have far more success than setting and maintaining the humidity control on a manual unit.

Incubating Chickens Eggs

Chickens eggs have a 21 day incubation period (isn’t that amazing? Egg to chick in just 3 weeks!) and require a constant temperature of 37.5°C. Eggs will start to produce their own heat in the latter stages of development but the incubator thermostat takes care of this, keeping the temperature the same throughout the incubation period. Humidity should ideally be between 45 and 50%. Eggs need turning regularly by 180 degrees and you will need to do this yourself if the incubator doesn’t have an automatic turning mechanism. Expect 50% to 75% of your eggs to hatch, not all eggs will be fertile.

Hatching Eggs

Eggs need to be fertile so a cockerel needs to be running with the hens for a few weeks before eggs are taken for hatching. If you have a cockerel, you can collect your own hatching eggs from your chickens. Try to pick good looking ‘egg shaped’ eggs, this will help the chicks form and hatch correctly as mother nature intended. Keep nest boxes clean and don’t set any soiled eggs. If you don’t have a cockerel or would like a different breed, there are many hatching eggs for sale online on sites such as eBay but keep in mind that just about anyone and everyone sells eggs so birds vary in quality between sellers. Hatching eggs travelling through the postal system can be damaged internally and either not develop or die before they hatch. These are often called dead in shell.

Incubation tips:

  • Before you put your eggs into any incubator, make sure it has been sterilised with an incubation disinfectant (or as a minimum warm soap and water if you don’t have this). This will kill bacteria that multiply rapidly in the warm temperature of the incubator.
  • Plug in your incubator and make sure the temperature is steady at 37.5°C. Always leave it to run overnight to settle before putting eggs in.
  • Keep water reservoirs topped up so that adequate humidity can be maintained at all times.
  • Candle eggs before putting them into the incubator. Cracked or damaged eggs do not hatch and should be removed after candling (see below for more information on candling).

Candling Eggs

candling

Candling an egg in the dark using a special candling torch. Blood vessels and the embryo can be clearly seen after a week.

Fertility of eggs cannot be determined before incubating them. It is easiest to see development of the embryo after a week. The most critical period of incubation is the first week so if you do decide to candle your eggs before a week then be very careful with them and do not overheat them. Eggs with blood rings, cloudy eggs or clear eggs (infertile) should be removed when detected. The photo to the right shows an egg that was candled after 8 days. If you can’t see much, do this in the dark. It may also help to tip the egg gently from side to side so you can see the inside of the egg moving and see what are patches on the egg shell and what is inside. The developing spider like veins and a small dark embryo can be seen. If you look carefully and have a bit of luck with the positioning of the embryo, you can often see a small heart beating away. I usually candle after 7 days and again at around 14 days. There is more information on a separate page about candling eggs.

The Air Sack

An Air Sack is formed at the broad end of the egg shortly after an egg is laid. There is a membrane between this and where the chick is developing. When candling periodically through the incubation period, this is the best method of judging normal development and you will see this increase in size up until the point that the chick breaks through into this air sack.

The Hatch

  • A chick will usually ‘pip’ the shell a few hours after breaking into the air sack so she can breathe but a full hatch can take 12 or more hours from this point so be patient.
  • If humidity has been set too high during the incubation period, the chick may pip the shell underneath the shell and drown in the fluids before he can get his beak out of the shell.
  • If the humidity has been too low, the air sack will be too large and the chick will be under-developed  and may become stuck to the shell, too weak to break free.

If a chick has pipped but does not make any progress, wait 12 hours, then consider breaking the top part of the shell away (but no more…) Some say do not help weak chicks as you are breeding weakness into your flock but there are many reasons why eggs don’t hatch. If it is a humidity problem like this or the line is particularly in-bred (often found with exhibition strains) then a little help can usually be given without detrimental effect.


The film above is speeded up and shows the final moments of a Copper Black Marans egg hatching in an RCOM King Suro incubator. As you can see with the King Suro, there is a good viewing window to see what is going on! It is my favourite incubator and is incredibly well priced.

And finally…

  • Do not remove hatched chicks until they are fully dried out. Chicks do not need to eat for 24 hours. This is why they can be shipped around commercially as ‘day old chicks’.

Good luck with your hatch!

Do you have any tips on hatching eggs? Please leave me a comment below.

97 Comments

  1. I have two barnevelder chicks who hatched today (one at 6am one less than an hour ago). The older chick appears to be pecking at the new one. (I have a Brinsea mini incubator). Is there anything I can do to stop this behaviour?

    • Just wanted to add, I know that they have to sort out the “pecking order” I just wanted to give the new born a little rest so it could recover.

    • Provide food, they should find this more interesting. They do peck a little, more out of exploration than anything else and I wouldn’t worry unless it causes bald patches or worse.

  2. if you have eggs with chicks in them and your hen is still broody will your hen happily hatch them herself

    thank you in advance

  3. i have 2 eggs (fertilised) i got from a farm they are meant to hatch today but haven’t seen any cracks should i brak a bit

    • No, never interfere with eggs. They should hatch on their own if all went well. If you interfere, the yolk sack won’t be fully absorbed and they will bleed. Even a small crack causes the chick to dry out and stick to the shell near the crack.

  4. I have a Little Giant Air Forced Incubator, but I’m having serious trouble keeping the temperature steady at the last few days of incubation. I’ve learned that the chicks inside the eggs already start producing their own heat but my problem is within the temperature regulating system itself, it seems not to be working anymore!! TERRIBLE INCUBATOR!!

  5. I HAVE JUST PURCHASED A FORCED AIR INCUBATOR BUT THERE IS NO GADGET TO MESURE HUMIDTY, HOW DO I FIND OUT AT WHAT HUMIDITY IS T RUNNING AND HOU CAN I INCREASE OR DECREASE THE HUMIDITY IF NEEDED?
    DOES ANYONE KNOW?
    THANK YOU

    • You will need to purchase a hygrometer from somewhere. The cheap plastic units usually supplied are often inaccurate anyway. Digital hygrometers are usually better.

      To increase humidity, you need a larger surface area of water inside. There is also usually a vent that can be adjusted for fine adjustments.

  6. i fancy building my own incubator, looked at a few on different sites do you have any advise on the correct build… would a fan assisted one be better
    cheers graham

      • merit of fan in an incubator,it takes you to close to 95% hatchability.I said this because,am manufaturer of small/induatrial ones.

        • I have a still air Britasea 42 egg incubator. Do you think it would benefit from installing a small fan inside?

          • No, it shouldn’t need it. There should be air vents somewhere that allows a small amount of fresh air in from the outside.

            Still air incubators work differently, the air stratifies in layers so it is much warmer at the top of the egg to the bottom.

  7. Bought my first eggs on Saturday, got my incubator today (Monday) looking forward to seeing the first chicks hatch. Reading about brooders can I use a large cardboard box with a smaller one inside and newspaper on the floor.

    • I don’t see why you need the box inside the box? A big box will do – heat lamp over head, well secured and away from the edge of the box. Make sure chicks are fully dried out before putting them in there. If the chicks are too hot, they will not go directly under the heat lamp, if they are too cold they will huddle together directly underneath it.

  8. Hi I have 3 6wks pekin chicks currently on chick crumbs when do I give them growers pellets ? and when can they have ‘treats’

    cheers

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