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The 4 Chicken Developmental Stages

Raising chickens can be a fascinating hobby. The more you do it, the more you want to learn about your feathery flock. What makes chickens tick? Where do they come from? What kind of lifespan do they have? These and other questions are incredibly interesting. When you keep backyard chickens, knowledge is power. Learning about your chickens’ life cycles can help you raise them properly with all the right food, shelter, and care they need at each specific stage of their lives. Even if you don’t plan on raising chickens from eggs, you can still benefit from knowing the ins and outs of chicken developmental stages. Feed your curiosity and move one step closer to becoming a chicken expert with this overview of a chicken’s life from egg to adult.


Whether the chicken or the egg came first doesn’t matter—nowadays, every new fuzzy baby chick starts as an egg. A chicken embryo starts to develop even before the hen lays her egg. Once the hen lays, this development halts until the egg encounters the right conditions to continue developing, such as in a broody hen or a safe incubator.

After incubation begins, the embryo spends the first few days developing its form. The head and backbone will gain definition while the first stages of organ development occur. By the fifth day of incubation, the embryo will have all its necessary organs and identifiable parts. Throughout the next several days, development continues as the embryo becomes more recognizable as a developing chick. Wings and feet become more defined, feathers appear, and the beak hardens.

Around the 14th day of incubation, the embryo starts to move into position for hatching. After roughly 20 days of incubation, the chick is ready to hatch. During this time, the baby chicken will absorb nutrients from the eggshell to sustain itself for its first days alive. The incubation period finishes as the chick begins to peck free of its shell and step out into the air to join the world.


Your chick will emerge from its egg wet, weak, and tired, but it won’t stay that way for long. If you decide to leave your newborn chicks with the mother hen, you won’t have to do very much. Give your hen a safe place to raise her brood and provide crumbs of starter feed for the chicks. You should also set up a clean water supply for both your hen and her babies.

If you don’t have a hen to protect the chicks, you’ll need a chicken brooder to give them the warmth and security they need during their first weeks. Chicks can’t produce body heat the way adult chickens can, so a heat source is essential. Start the brooder at 95 degrees Fahrenheit for the initial week. Gradually decrease this temperature every week until your chicks have acclimated to ambient temperatures. Your brooder also needs a clean supply of food and water. Chicks are clumsy and messy, so you might have to check in multiple times a day to ensure their home stays clean. This is another vital step, as chicks are more susceptible to certain diseases, such as coccidiosis. Finally, make sure the brooder stays dry. Fresh bedding and proper ventilation will help prevent mold, mildew, and other dangerous moisture issues.

In the early weeks, you will see the chicks grow and start to replace their fuzzy chick down with feathers. After a week or two, you can start the process of adjusting your chicks to normal coop life by adding a small perch to their brooder. You can also add chick grit to their feed. Just make sure your chicks are still getting the protein, amino acids, and other key nutrients they need for healthy growth and development.


After the adorable chick stage comes adolescence. A chicken’s teenage years occur between weeks five and eighteen. During this time, your young birds will go through many visible changes. Skinny legs and awkward proportions often define a pullet—a young hen. Never fear, as your adolescent chicken will keep growing as it develops new primary feathers.

This is also when chickens start experimenting with the pecking order. If you have a brood of adolescent chickens, they’ll develop a pecking order. However, you can prevent them from having to go through this ordeal twice—once among themselves and again with the entire flock—by introducing them to the rest of the flock. Once your pullets are roughly two-thirds of the size of the adults, you can integrate the two groups. Just keep an eye out for excessive bullying. If you have cockerels—teenage males—be sure to introduce them to the flock before they start crowing. This will prevent fighting, especially if you already have another rooster in the flock.

You should keep your adolescents on starter feed during this time. Like chicks, teenage chickens need plenty of protein in their diet. However, take care not to give them too much calcium, as this can impede their development.


When your young birds reach the eighteenth week of their life, you can officially call them adults. This is the time to switch them to regular feed or a specialized layer feed to help your hens lay stronger eggs. During this time, your female chicks will become adults capable of laying their own eggs. While you might experience some minor squabbles within the flock, your new adults will quickly settle into their routine at this point.

Once your chickens reach adulthood, the first year will be relatively average. Your new hens will lay regularly until around 18 months, when they experience their first molting. During molting, your hens stop laying as they shed and regrow their feathers and rebuild their nutrient reserves. After their first molting, you can expect your hens to molt once a year starting in the fall as the days grow shorter.

Most chicken breeds are productive egg layers for their first year or two of adulthood, but production will eventually decline. Once your hens reach retiring age, you’ll have to decide what to do with them. In addition to no longer laying eggs, older chickens are slower and have less energy. They’re also prone to arthritis and other aging conditions. That said, there’s no rule that you must get rid of your retired hens. These old girls still make entertaining pets—and excellent garden pest control—throughout the next several years. If you decide to keep retired hens instead of butchering them for meat, you can expect them to live to about five to eight years old.

Raising flock members from an egg can be a rewarding and unforgettable experience. With this guide to the chicken developmental stages, and all the best supplies from Stromberg’s Chickens, we hope to help your flock thrive for years to come. Contact us today for anything you need regarding poultry breeding and rearing.

The 4 Chicken Developmental Stages