Some extreme vegans have a new strategy to make people quit their animal product habit: they spread gross and false information about what they are eating. 

I think this is a horrible and unnecessary way to persuade people, even though I don’t eat much meat or dairy myself. I believe there are much better alternatives than this.

Please, dear vegans, don’t stoop so low! 

This idea came to me when I was browsing the internet for some information about eggs and their benefits, as part of my blog research. 

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I stumbled upon an article that shocked me and motivated me to write this.

The article, clearly written by a vegan, stated boldly that “an egg is nothing but a chicken’s menstrual discharge”, and even provided some scientific arguments to support this claim.

Can you believe that? They said that when a chicken lays eggs, it’s menstruating!

That sounded ridiculous and false to me, but the article had a scientific explanation that seemed to make sense. (or so I thought)

But I still couldn’t accept that I had menstrual blood for breakfast. So I decided to do my own research.

After reading through tedious papers on embryology and avian reproduction, I finally found out the truth. And I’ll be sharing that with you in the course of this article!

No, eggs are not chicken periods and chickens do not menstruate.

Menstruation is a natural process that only occurs in females of some mammals, such as humans, chimpanzees, monkeys, bats and elephant shrews. 

A chicken is not a mammal. No other animals besides mammals have been found to menstruate.

But of course, this simple statement “Menstruation is exclusive to mammals and chickens do not menstruate” may not be enough to convince you!

So I came up with a simple method that is based on common sense, and I will use it to show you that chickens do not have periods.

For this method, we first need to briefly understand how pregnancy and menstruation work in mammals, and how a chicken can lay eggs. 

Then, we will compare chickens and menstruation and see if there is any connection.

Some female mammals, when they reach sexual maturity–a stage in mammalian development called puberty–start a process called the menstrual cycle (in humans) or estrus cycle (in animals).

At the start of this cycle, one or more eggs are released from her ovaries–the part of the reproductive system that makes eggs, and are sent to a place where they can be fertilized (the process that makes eggs into babies).

If the egg or eggs meet a sperm during this time, they will be fertilized and moved to a special place that was prepared while the egg was traveling; to live, get nourished and grow into a baby. This means the mammal is pregnant.

If the egg or eggs do not meet a sperm (which means no sexual activity happened), then the egg is not fertilized and cannot become a baby. 

The reproductive system recognizes this as a failed attempt and gets rid of this unfertilized egg and its special place through the reproductive part or by absorbing it, so that a new cycle can start. 

In this case, the mammal is having her period.

The whole process (cycle) can last up to a month depending on the mammal. 

And it happens again and again until the female mammal reaches menopause; a time in her life when she cannot reproduce naturally anymore.

Now,

Let’s look at how birds reproduce.

Similar to menstruating mammals, the formation and release of eggs (yolk) from the ovary in a hen happens regularly and when they become sexually mature. This means that they don’t need sexual activity to make and release eggs (yolk). (We will call the eggs in the ovary yolk from now on)

But unlike mammals, it doesn’t happen in fixed cycles, so it can’t be called a menstrual cycle.

When yolk(s) are made in a chicken’s ovary, they are sent to an oviduct which is like a production line where the egg white, chalaza, and shells are added to it.

The start of the oviduct is the infundibulum; the place where the egg can meet a sperm for fertilization.

After the time is up, the yolk is moved down fertilized or not to the other parts of the oviduct where it becomes a complete egg and then pushed out through the reproductive part (laying eggs)

Now, you can see that with hens, something is different. An unfertilized egg goes through the same reproductive steps as a fertilized egg. That is not what happens in all menstruating mammals. Unfertilized eggs are seen as waste and removed.

Fertilized eggs are the key to pregnancy in mammals, while unfertilized eggs are the key to menstruation in mammals. 

A chicken laying an egg, on the other hand, can have either a fertilized or an unfertilized egg. 

So does that mean a chicken is somewhere between pregnant and menstruating? 

Not exactly. A chicken can’t be both hatching chicks and having its period. Mammals don’t do that. 

So a chicken laying eggs is either pregnant or menstruating, not both. 

Let’s see how we can tell the difference.

One might think that a chicken lays eggs to hatch them into chicks, but this only makes sense for fertilized eggs, not unfertilized ones. 

Likewise, one might think that a chicken lays eggs to get rid of them, like a period, but this only makes sense for unfertilized eggs, not fertilized ones. 

So how can we explain why a chicken lays eggs?

A better way to approach this question is to look at what a chicken does after laying a bunch of eggs. 

It doesn’t matter if the eggs are fertilized or not, the chicken will sit on them and try to hatch them. It may even become very protective and stop eating, risking its own health. 

This shows that a chicken doesn’t know if its eggs are fertilized or not. It just follows its instincts and wants to hatch them.

This also shows that a chicken doesn’t have a way to detect and get rid of unfertilized eggs, unlike mammals that have a menstrual cycle. 

If it did, it wouldn’t try to hatch its own period! So we can conclude that chickens do not have periods, they just lay eggs.

First off, I’ll propose two hypothesis,

If we can prove that a hen lays an egg for the same reason that a female mammal has a period, it means that hens have periods and eggs are their period waste. 

If also, we can prove that a hen lays an egg for a different reason than a female mammal has a period, it means that hens do not have periods and eggs are not their period waste. 

If you agree with this logic, then we can proceed. If not, you can stop here.

The basic idea is this.

Periods happen because the egg is not fertilized. 

The body senses that the egg is not needed and gets rid of it along with the lining of the uterus that was ready to support it. 

This clears the way for a new cycle to start and a new lining to form for the next egg.

So the main factors that determine why a period happens are: “unwanted” and “unfertilized”.

A female mammal has a period because she is discarding tissues and an unfertilized egg or eggs that she doesn’t need.

So we will examine why a hen lays an egg and see if it matches this definition.

The main reason why a chicken lays eggs is to reproduce. To make adorable baby chicks.

How do we know?

Because an unfertilized egg in a chicken goes through the same process as a fertilized egg, we can infer this:

“Every egg that a chicken lays is meant to be fertilized”, and guess what? a chicken will naturally sit on its eggs, whether they are fertilized or not, hoping to hatch them into chicks. 

And while doing this, it can become very stubborn, refusing to eat and even risking its own health.

This shows that the statement “every egg that a chicken lays is meant to be fertilized” must be true, otherwise, why would a chicken try to hatch its unfertilized eggs?

But if all chicken eggs are meant to be fertilized, yet some end up being unfertilized, what system is there to detect and remove these unfertilized eggs in a chicken’s reproductive system? 

I’ll let you think about that.

So since we have established that every egg that a chicken lays is meant to be fertilized, this proves that the first statement about chickens laying eggs for the main purpose of making chicks is true.

Why does Period Occur? To get rid of unfertilized eggs and the lining of the uterus that are not needed in the body, and to prepare the body for the next cycle.

Why Do Chickens Lay Eggs? To hatch them into chicks.

It’s clear that there is no connection between these two reasons.

A chicken’s natural purpose for laying eggs, whether they are fertilized or not, is to potentially make them into healthy chicks, not to dispose of unfertilized eggs that it doesn’t need.

So comparing chickens to periods is completely wrong.

But some people online argue…

“That chickens lay unfertilized eggs and humans release unfertilized eggs during periods, so eggs must be periods”

But this argument ignores why mammals have periods and hens lay eggs, and the fact that hens also lay fertilized eggs.

But let’s say we agree, that when a chicken lays a fertilized egg, it’s reproducing, and when it lays an unfertilized egg, it’s having a period.

This still leaves one question unanswered.

Why does a chicken try to hatch its period?

The answer is no. It’s a common misconception, and here’s why it’s incorrect. Chickens’ ovaries are simply the site where the egg yolk is produced. 

The entire reproductive system of a hen, including its ovary and oviduct, plays a part in crafting the egg we’re familiar with. 

The yolk matures in the ovary before traveling down the oviduct where it gains layers of albumen (egg white) and finally the shell. 

Once fully formed, it passes through a shared exit pathway known as the cloaca – used for reproductive, urinary, and digestional purposes – before being laid.

Again, it’s a resounding no. The majority of eggs found on supermarket shelves are unfertilized; they do not contain an embryo capable of growing into a chick.

In the event an egg is fertilized, development into a chick only begins when a hen incubates it by sitting on it- something that doesn’t occur in commercial operations. If not incubated within several weeks, any present embryo would perish—so rest assured you’re not eating or harming any prospective chicks.

So if eggs aren’t baby chickens or chicken ovaries- what exactly are they? At its most basic level, an egg is primarily composed of protein and water with additional nutrients like fats, vitamins and minerals. 

The yellow yolk houses about 60% of an egg’s total protein and harbors most of its fat content along with cholesterol and calories. 

On the other hand, the glossy egg white holds roughly 40% of the total protein content along with water-soluble vitamins and minerals. 

Wrapping up this nutrient-packed package is a durable shell made mostly from calcium carbonate- lending strength to protect potential life inside.