Do eggs have to stay warm to hatch?

Eggs must be exposed to consistent and optimal temperatures to hatch, as the embryo inside relies on the environment to provide heat for its development. The ideal incubation temperature for many birds’ eggs is about human body temperature, 98.6 degrees F, and any significant deviation from this temperature can affect the hatching process.

Understanding Egg Incubation

To ensure successful hatching, it’s essential to understand the incubation process and the factors that influence it. Temperature, humidity, and turning are critical components of egg incubation, and any disruption to these factors can impact the development of the embryo.

Frequently Asked Questions

The following FAQs provide additional information on the hatching process and address common concerns and questions related to egg incubation.

1. Can eggs get cold and still hatch?: No, below about 27°C (80°F), no embryonic development takes place, and ice crystals can form in the egg, causing permanent damage to internal structures.
2. Do eggs need constant heat to hatch?: An incubator that is run warm, constantly averaging a bit above 100.5 degrees F, will tend to produce an early hatch, while one that is run cold, a bit below 100.5 degrees F, will tend to produce a late hatch.
3. How long can hatching eggs go without heat?: Some embryos can survive at temperatures below 90°F for up to 18 hours, so it’s essential to continue incubating the eggs after a power outage and candle them 4 to 6 days later to check for further development or signs of life.
4. Why do eggs need to be kept warm to hatch?: The organism inside an egg has no ability to regulate its temperature and relies on the environment to provide heat, making an external source of warmth necessary for the embryo to develop.
5. What can happen if the eggs are not kept warm?: Storing eggs in cool temperatures and then leaving them out at room temperature can cause condensation, promoting the growth of bacteria on the shell, which can get into the egg and make it unhealthy for consumption.
6. Why do market eggs not hatch?: Supermarket eggs are most likely not fertilized, as there are no roosters in large commercial egg barns, and no sperm has reached the egg, making it impossible for the egg to develop.
7. What should you not do when hatching eggs?: Do not turn eggs during the last three days before hatching, as the embryos are moving into hatching position and need no turning, and keep the incubator closed during hatching to maintain proper temperature and humidity.
8. How do you know if an egg is not going to hatch?: Break open unhatched eggs to check if the egg was fertile, at what stage the embryo died, and possibly why, as infertile eggs will contain entirely yellow contents with no signs of an embryo or blood.
9. How do you tell if a chick has died in the egg?: When candling, if the blood vessels have collapsed, it’s likely the chick has died, but as long as you’re still seeing blood vessels, the embryo is alive.
10. Is 80 humidity too high for hatching eggs?: 70-75% relative humidity is a good target during the hatching period, and increasing humidity during hatching can help the chick emerge from the egg more easily.
11. What happens if egg incubation is interrupted?: Eggs cool when incubation is interrupted, but this is not usually harmful, and few birds incubate continuously, so it’s essential to continue incubating the eggs after a power outage.
12. Will a hen sit on dead eggs?: Birds can hear the babies in the eggs and will not stay on dead or unfertilized eggs in vain hope of hatching them, so if a hen sits on eggs that won’t hatch, she’s doing it for instinctual reasons.
13. How long can fertilized eggs be left unattended?: Hatching eggs can be left for up to 10 hours and will still usually hatch, but it’s essential to provide a consistent and optimal environment for the embryo to develop.
14. Can eggs get cold then warm?: Once an egg has been stored in the fridge, there’s no going back, as condensation forms on the outside of the shell, making an incredibly rich broth for any bacteria present on the surface of the egg.
15. What is the longest it can take for a chicken egg to hatch?: The incubation period for chicken eggs is 20 to 21 days, and increases up to 30 days for other poultry, so it’s essential to be patient and provide the optimal environment for the embryo to develop.