Do Chickens Have Periods?

Ever wondered if chickens have a menstrual cycle and whether eggs are chicken periods? Well, the truth is chickens don’t have a menstrual cycle. Also, eggs are not equivalent to periods, which certain female mammals experience.

You may be probably wondering if chickens have periods due to the recent PETA campaign slogan that suggested that eggs are chicken periods. Simply put, chickens are birds and not mammals. Mammals give birth to live young ones who develop in a uterus with a soft tissue lining.

If no egg gets fertilized, the tissue lining sheds, resulting in blood flow. Birds, chickens included, don’t have a uterine lining or a uterus and thus can’t experience menstruation. Here are more insights on whether chickens experience menstruation and menopause.

Do Chickens Have Menstrual Periods?

The menstruation process is nature’s own way of alerting the female about their body’s health and ability to nurture offspring. If you own pets, you may have noticed that mammals such as rabbits, cats, and dogs get periods. But is this the same case with birds, chickens included?

Chickens don’t bleed internally during ovulation, unlike some mammals and dogs. It is wrong to compare eggs to menstruation since birds have a different reproduction cycle compared to mammals that menstruate.

Menstruation and egg laying are usually meant for the body to dispose of an unfertilized egg. The egg comes in blood form in menstruating mammals and as an egg in birds (whether fertilized or not). Even more, menstruation is usually described as the discharge of the uterus lining, something that birds don’t experience.

To be precise, an egg cell is released into the human ovary after every ovulation. Ovulation happens when follicle-stimulating and luteinizing hormones peak in the reproductive organ. The egg cell will travel through the fallopian tube with the hopes of being fertilized.

If it’s fertilized, it will be attached to the uterus lining. And if it’s not, it will flow through the vagina as menstruation.

All in all, menstruation is dependent on the type of reproductive system the animal has. Birds aren’t evolved to shed uterus lining as menstruating mammals are.

The Menstrual Cycle of Chickens

Though chickens don’t have a menstrual cycle, they create and pass eggs that are relative to their body weight and size. The egg-laying process is thus physically exhausting to their bodies. This is especially true in hens bred to lay an abnormally high number of eggs.

A chicken’s reproductive organs differ greatly from the human female reproductive organ. The process eggs are created in these organs also varies greatly with the entire human reproductive process.

The main difference between a chicken’s and a human female’s reproductive system is that chickens don’t have a defined cycle for laying eggs. Female mammals also undergo pregnancy once the egg cell is fertilized, while chickens lay eggs whether or not the eggs are fertilized.

Chickens have the ability to lay so many unfertilized eggs since they were selectively bred for this purpose. Breeders have been altering their DNA for several years to improve their egg-laying abilities. Through selective breeding, we now have chickens that are dual purpose, which means that they can be reared for both eggs and meat.

Are the Eggs the Periods of Chickens?

Most biologists agree that eggs are not the equivalent to periods that menstruating mammals get. And since hens and other birds produce follicles during ovulation, they don’t get periods like other animals. Instead, the ovulated follicles flow through their bodies and end up coming out as unfertilized or fertilized eggs.

Eggs develop from the ovary and are released when eggs reach full sexual maturity, just like in mammals that menstruate. In this case, a chicken doesn’t need to have sexual intercourse before its ovary forms and releases eggs. Also, egg production happens recurrently, unlike in menstruating mammals.

A menstrual cycle refers to natural changes in the production of hormones and the uterus and ovaries of a female menstruating mammal that makes pregnancy possible. It is usually the first day of a period. Since chickens don’t have a menstrual cycle, it’s wrong to associate the eggs that are laid with periods.

Instead, eggs created in the hen’s ovary flow down an oviduct, where the shells, chalaza, and egg white are added to it. The egg lies in the infundibulum, where it may get into contact with a viable sperm for fertilization to happen. If the waiting period elapses, the yolk passes down unfertilized or fertilized into other parts of the oviduct, and an egg is formed before being expelled by the chicken.

From these explanations, you can conclude that egg laying in chickens involves both unfertilized and fertilized eggs. It slots somewhere in the middle. Also, it’s impossible for a chicken to have a period and try to hatch chicks at the same time.

Do Chickens Have Menopause?

It’s true that most animals that live to older ages go through certain changes in their body, affecting their reproductive abilities. In female humans, the period in which these changes start occurring is referred to as menopause. Henopause is the equivalent of menopause in chicken.

However, there are several factors to consider as you try to determine when your hen will undergo henopause. It is the point at which your hen will stop laying eggs.

Though your chicken’s egg production will start decreasing after one year, it may lay more eggs until it gets to the age of 5 or 7. An older hen produces fewer eggs gradually, though they are usually large in size. As the egg production decreases, you may either choose to keep the chicken as a non-producing pet or slaughter it.

Either way, expect your chickens to stop laying eggs if the temperatures aren’t favorable and if it fails to get not less than 12 hours of daylight. It’s therefore important to rear egg-laying hens in a brightly lit and warm area to avoid impacting their egg production abilities.

Depending on your location, you should consider choosing the best egg-laying breed. The breed should also withstand the climatic conditions in your area. Also, learn more about the hen’s brooding and egg-laying tendencies before introducing it to your flock.

Why is My Chicken Bleeding?

Though it’s uncommon for chickens to bleed, if you spot any bleeding in your flock, it’s likely to have an injury or a treatable condition. The bleeding is likely to occur from the vent. It’s also wrong to associate bleeding in chickens with menstruation.

A bloody bottom in your chicken may suggest that something is wrong with their reproductive or digestive system. Its signs may also be similar to those that occur with pain. Consult with a veterinarian if the bloody bottom is accompanied by signs such as lethargy, lack of appetite, hen refusing to come out of the coop, and hen huddling with its feathers fluffed up.

Don’t hesitate to take chickens with bleeding vents to a veterinarian for urgent medical attention. You should also schedule a vet appointment when the bloody bottom is accompanied by symptoms such as diarrhea, drooping wings, lethargy, and injuries.

Common causes of a bloody bottom may include pecking, egg laying, and prolapse. It’s common for the vent in your young hens to appear swollen or red after it’s pecked at by other birds. Also, an egg-laying chicken may discharge blood or have its cloaca or vent pushed out due to a prolapse.

A young egg-laying hen may often burst blood vessels during the first few days of being broody. You may also notice blood smeared on the feathers or eggs. There’s nothing to worry about when this happens since it rarely persists as the hen lays more eggs.


The fact remains that chickens don’t have periods and can produce unfertilized or fertilized eggs since they have been selectively bred for this purpose. Menstruation is only limited to humans and some mammals. Also, a chicken’s egg laying production starts to decline as it gets old and stops completely at the peak of henopause.

avatar James
Hey, I'm James, a hardworking homesteader for more than 30 years. I enjoy the feeling of accomplishment that comes from tending my flock. I've raised chickens and ducks for eggs and meat for many years. I also have experience with other poultry too. Learn more

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