What Happens During Egg Incubation?
Egg incubation is a carefully controlled process that allows embryos to develop inside fertilized eggs until chicks hatch successfully. During incubation, temperature, humidity, ventilation, and egg turning all work together to support healthy embryo growth.
Chicken eggs usually require about 21 days to hatch. Throughout this period, embryos gradually develop from tiny cells into fully formed chicks ready to hatch. Understanding each incubation stage can help beginners improve hatch rates and avoid common incubation mistakes.
Days 1–7: Early Embryo Development
During the first week of incubation, embryo development begins rapidly inside the egg. Blood vessels start forming, and the embryo gradually becomes visible during candling.
Stable temperature and proper humidity are especially important during this stage because embryos are very sensitive to environmental changes. Eggs should also be turned regularly to support healthy development and prevent embryos from sticking to the shell membrane.
Days 8–14: Growth & Movement
Between days 8 and 14, embryos continue growing quickly and become more active inside the egg. During candling, movement and larger dark areas may become visible as the chick develops.
Humidity and ventilation remain important during this stage to support healthy growth. Eggs should continue turning regularly until the final incubation stage approaches.
Days 15–18: Final Development Stage
During the final development stage, chicks grow rapidly and begin positioning themselves for hatching. The air cell inside the egg becomes larger as moisture loss continues throughout incubation.
By day 18, egg turning is usually stopped in preparation for lockdown. Stable humidity and minimal incubator disturbance become increasingly important during this stage.
What Happens During Lockdown?
Lockdown is the final stage of incubation before chicks begin hatching. During this period, egg turning stops and humidity levels are increased to help chicks hatch successfully.
Opening the incubator too often during lockdown can reduce humidity levels quickly and make hatching more difficult. Maintaining stable conditions is extremely important during this stage.
Day 21: Hatch Day
Around day 21, chicks begin pipping through the shell and gradually hatch from the egg. Some chicks may hatch slightly earlier or later depending on incubation conditions.
It is important to avoid helping chicks hatch too early unless absolutely necessary. Newly hatched chicks should remain inside the incubator until they are dry and fluffy.
When Should You Candle Eggs?
Candling is commonly performed around days 7 and 14 to monitor embryo development inside the egg. During candling, blood vessels, movement, and air cell growth can become visible.
Candling helps identify infertile eggs or embryos that stopped developing during incubation.
Common Timeline Mistakes
Many beginners make mistakes by opening the incubator too often, stopping egg turning too early, or changing humidity levels too frequently.
Temperature fluctuations and improper lockdown preparation may also reduce hatch success. Following a consistent incubation schedule can help improve hatching results.
Caring for Chicks After Hatch
After hatching, chicks should remain inside the incubator until fully dry. Once dry, they can be moved into a warm brooder with clean water and chick starter feed.
Maintaining proper brooder temperature during the first few weeks is essential for healthy chick growth.