Have you ever looked at your backyard chickens and wondered about their incredible journey from egg to adult? The life cycle of a chicken is truly a fascinating process that never ceases to amaze me, even after years of raising these feathered friends. Whether you’re a seasoned chicken keeper or just curious about these amazing creatures, understanding their life cycle helps us appreciate the small daily miracle that is chicken life.
I’m going to walk you through each stage of a chicken’s life cycle – from the moment of fertilization all the way to adulthood Let’s dive into this egg-citing journey together!
The 5 Key Stages in a Chicken’s Life Cycle
The life of a chicken can be divided into five distinct stages:
- Egg Fertilization
- Egg Embryo Development
- Chick Stage
- Pullet/Cockerel (Teenager) Stage
- Hen/Rooster (Adult) Stage
Let’s explore each stage in detail.
Stage 1: Egg Fertilization – Where It All Begins
The chicken life cycle begins with fertilization. This process is actually quite fascinating and involves some interesting chicken courtship behaviors!
Roosters will try to court hens through various displays and rituals One common behavior is “tidbitting,” where the rooster finds something interesting to eat, picks it up, and drops it repeatedly while calling the hens over He’ll also perform a courtship dance by dropping one wing to the ground and shuffling around the hen.
Hens are selective in choosing their mates. They consider factors like:
- The rooster’s appearance
- His attentiveness
- His ability to find food
- His potential as a flock leader
When a hen is interested, she’ll squat in submission. The mating itself is brief (less than a minute) and involves the rooster mounting the hen from behind, using his beak to hold onto her head or neck feathers.
Once mating occurs, the sperm begins its journey to fertilize the egg. Fertilization takes place in the infundibulum – the part of the reproductive tract that follows the ovary. Since an egg only remains in the infundibulum for about 15 minutes, this creates a small window of opportunity for fertilization.
If you don’t have a rooster, don’t worry! Your hens will still lay eggs, they just won’t be fertilized and therefore won’t develop into chicks.
Stage 2: Egg Embryo Development – The Miracle Inside the Shell
Once fertilized, the egg begins its development process. The hen lays the egg, and if she becomes broody (a natural maternal instinct), she’ll sit on the eggs for 21 days, keeping them at the perfect temperature and turning them regularly to ensure proper development.
Here’s what happens inside that egg during those 21 days:
Days 1-7: The Foundation
- Day 1: Development of the germinal disk begins
- Day 2: Tissue development starts and blood circulation begins
- Day 3: The heart starts beating and blood vessels become visible
- Day 4: The amniotic sac begins developing
- Day 5: Elbows and knees develop, and eyes become visible during candling
- Day 6: The beak starts forming and voluntary movement begins
- Day 7: The comb begins to grow
Days 8-14: Taking Shape
- Day 8: Feather follicles appear and ear canals open
- Day 9: Claws develop and the embryo now looks bird-like
- Day 10: Egg teeth and claws fully form
- Day 11: Tail feathers start growing
- Day 12: Feathers begin appearing across the body
- Day 13: Leg scales appear and the body has a light covering of feathers
- Day 14: The head turns to the pipping position
Days 15-21: Final Preparations and Hatching
- Day 15: The chick consumes egg white for nutrition
- Day 16: The chick is completely feathered
- Day 17: Egg white is absorbed and the head positions between legs
- Day 18: The chick is almost fully grown, with the yolk sac still outside the body
- Day 19: The yolk sac moves into the body, and the embryo occupies all space except the air cell
- Day 20: Yolk sac is absorbed, umbilicus closes, and the embryo starts breathing air – pipping begins!
- Day 21: Hatching day! The chick breaks through the shell, usually within 18 hours
This whole process is a small miracle, and it still amazes me every time I see it happen in my own flock.
Stage 3: The Chick Stage – Fluffy Beginnings
Once hatched, the wet chick quickly dries off and transforms into an adorable ball of fluff. If a mother hen raised them, she’ll teach them everything they need to know – what to eat, what to avoid, and how to recognize dangers. She’ll keep them warm under her wings during the first days of life.
If you’re raising chicks without a broody hen, you’ll need to provide:
- A brooder with a heat source (95°F for the first week, then reduce by 5°F each week)
- Chick starter feed (higher in protein for proper development)
- Fresh, clean water at room temperature
- Protection from drafts and predators
Chick development is incredibly rapid:
- By week 2, they’ll start sprouting their first real feathers
- Between weeks 3-4, they acquire more feathers and grow rapidly
- By week 5, they should be fully feathered and able to regulate their own temperature
- Around week 8, they can spend more time outside (in a protected area) and try different foods
During this stage, chicks will also begin establishing their social hierarchy through gentle pecking and pushing. It’s fascinating to watch their unique personalities emerge during this time!
Stage 4: The Pullet/Cockerel Stage – Awkward Teenagers
Around 4 weeks of age, chicks enter their “teenage” stage and become pullets (females) or cockerels (males). This awkward phase lasts about 12 weeks, and they’ll look rather gangly and disproportionate – kinda like dinosaurs!
During this stage:
- Sexual differences become more apparent
- They begin asserting themselves and establishing their place in the pecking order
- They grow rapidly but look somewhat awkward and uncoordinated
- Their adult feathering starts to develop
If you’re introducing these “teenagers” to an existing flock, wait until they’re about 2/3 the size of your adult birds. The introduction should be gradual, with plenty of space and hiding spots available. There will be some pecking and bullying as they establish their place in the hierarchy, but this is normal unless it becomes excessively violent.
Cockerels may try to challenge older roosters but are usually put firmly in their place. Similarly, pullets will need to work their way up the female pecking order.
Stage 5: The Adult Stage – Mature Chickens
The final stage of the chicken life cycle is adulthood. A pullet becomes a hen once she lays her first egg, which typically happens around 18-20 weeks of age (though this varies by breed). Similarly, a cockerel becomes a rooster when he reaches sexual maturity.
When hens first start laying, their eggs are often small and may be irregularly shaped. This is completely normal! Their reproductive system is still getting up to speed. During this transition period (around 16-20 weeks), you should switch them from starter/grower feed to layer feed, which has less protein but more calcium for strong eggshells.
A healthy hen can lay eggs for several years, though production typically peaks in the first 1-2 years and gradually declines afterward. Hens may stop laying temporarily during their annual molt when they replace their feathers.
The average chicken lifespan is 5-8 years, though some can live up to 10 years or more with proper care. Heritage breeds and dual-purpose chickens tend to live longer than high-production hybrid layers.
As chickens age, you’ll notice:
- Reduced egg production
- A more sedentary lifestyle
- Thicker legs and feet
- Some may develop arthritis
- Facial features may appear more “tired” or “aged”
How Long Do Chickens Live?
While I mentioned this briefly above, let’s talk more about chicken lifespan. Many factors affect how long your chickens will live:
- Breed: Heritage breeds typically live longer (5-8+ years) than production hybrids (3-5 years)
- Purpose: Laying hens often have shorter lifespans than ornamental breeds
- Care: Good nutrition, clean living conditions, and protection from predators can add years to their lives
- Health management: Regular health checks and parasite prevention extend lifespan
I’ve had several chickens live well into their 8th year! My oldest girl, a Rhode Island Red named Ruby, made it to 9 years and still laid an occasional egg in her final year.
Tips for Supporting Your Chickens Through Each Life Stage
Based on my experience raising chickens for many years, here are some practical tips for each stage:
For Eggs and Incubation:
- If incubating, maintain 99.5°F temperature and 50-60% humidity
- Turn eggs at least 3 times daily (or use an automatic turner)
- Stop turning eggs 3 days before hatch (day 18)
- Increase humidity to 65-70% during hatching
For Chicks:
- Keep the brooder clean to prevent disease
- Introduce grit when they start eating treats (week 2)
- Add a small perch around week 2-3 for practice
- Offer a clump of short grass with dirt attached for them to peck at
For Pullets/Cockerels:
- Provide plenty of protein for proper development
- Begin introducing them to the flock gradually (short, supervised visits)
- Make sure they have escape routes when integrating with the main flock
- Be patient with their awkward behavior – they’re just teenagers!
For Adult Chickens:
- Provide oyster shell free-choice for laying hens
- Check regularly for parasites
- Allow yearly molting without artificial light interference
- Give older birds easy access to food, water, and comfortable resting places
Common Questions About Chicken Life Cycles
Q: How long does it take for a chicken egg to hatch?
A: It takes 21 days for a chicken egg to hatch under normal incubation conditions.
Q: Can chickens lay eggs without a rooster?
A: Yes! Hens will lay eggs regardless of whether a rooster is present. The eggs just won’t be fertilized.
Q: At what age do chickens start laying eggs?
A: Most hens start laying around 18-20 weeks of age, though some breeds may start earlier or later.
Q: How can you tell if an egg is fertilized?
A: You can candle the egg (hold it up to a bright light in a dark room) after 5-7 days of incubation. A fertilized egg will show veins and a dark spot (the developing embryo).
Q: Do chickens recognize their owners?
A: Absolutely! Chickens are intelligent birds that can recognize up to 100 different faces, including their owners.
Final Thoughts
The life cycle of a chicken is truly one of nature’s most fascinating processes. From the microscopic development inside an egg to the fluffy chick and eventually the full-grown chicken, each stage offers something wonderful to observe and appreciate.
What stage of the chicken life cycle do you find most fascinating? For me, it’s always been the hatching process – seeing that first pip in the shell and watching as a determined little chick makes its way into the world never gets old!
When do hens begin to lay eggs?
During ideal day length (14-16 hours of light) and with adequate nutrition, housing, and management, hens (depending on breed) should begin producing eggs when they are18- 22 weeks old.
Are eggs laid every day?
Ovulation (release of the yolk from the ovary) occurs every 24 – 26 hours regardless of fertilization (so a rooster is not needed). A hen ovulates a new yolk after the previous egg was laid. It takes 26 hours for an egg to fully form (white and shell added), so a hen will lay an egg later and later each day. Eventually the hen will lay too late in a day for ovulation to be signaled. She will then skip a day or more before laying another egg.