Yes, eggs do come from chickens’ bums to put it bluntly. It’s not as gross as you might think though. When a hen is laying an egg, tissues from the uterus extend so the egg cannot be contaminated as it exits the cloaca.
The whole process a hen goes through from creating an egg to depositing it in a nesting box is nothing short of fascinating!
In this article, I’m going to explain how hens produce eggs, which ‘hole’ eggs come out of - as well as their pee and poop - and more!
How Do Eggs Come Out of Chickens?
To explain a little about chicken anatomy and their reproductive system, both hens and roosters only have one exit hole called the cloaca, or vent.
So, chickens do indeed pee, poop, and lay eggs all from the same hole.
It’s not quite as simple as that though, and don’t worry, chickens are not able to perform all of those bodily functions at the same time!
A chicken’s large intestines, where fecal matter is passed, and the oviduct, where eggs are passed, are two separate ‘channels’.
Both exit from the same hole, the cloaca, but it’s not possible for both to happen at the same time.
When a hen is pushing an egg out, the uterus lining is basically inverted and comes to the edge of the vent.
In doing so, it pushes down on the hen’s intestine and effectively closes the intestine, and makes it impossible for the hen to pass poop while laying an egg.
It takes a hen about 24-26 hours in total from starting the process of creating an egg to laying it.
Most of that time is spent inside the oviduct creating the shell. When a hen starts to actually push the egg out of its vent, it really doesn’t take long at all.
Related - How many holes does a chicken have?
Here is a video showing you a hen laying an egg, if you're interested. Don't worry, it's not very graphic!
Do Chickens Lay Eggs Out of Their Buttholes?
This is something I see said quite often, and while it’s a bit crude to word it like this - it’s pretty much true.
Except, chickens really don’t have ‘buttholes’. At least, not in the same sense as we do. But they do poop out of their cloaca, the same hole where they also lay eggs.
The main concern is that an egg will be contaminated, or that it’s gross - but you don’t need to worry about that.
Chickens have laid eggs the same way for thousands of years, and it’s never been a problem!
Sure, there are bacteria to be aware of such as salmonella, but the risk is incredibly low when chickens and eggs are cared for in sanitary environments.
Nature plays a role in making sure eggs are safe for consumption, too. When an egg is laid, it has a natural protective covering called a ‘bloom’.
The bloom protects the embryo inside the egg from bacteria seeping in through the porous shell, as well as regulating the loss of moisture from inside the egg.
This leads on to an interesting topic around how eggs are handled around the world. Across most of Europe, eggs are sold unrefrigerated because the bloom is left on the shell.
While in the U.S., for example, eggs are kept and sold refrigerated. This is because they are washed before being processed for sale, and this removes the bloom.
Pretty interesting, eh!
Related - Does poop on chicken eggs mean they are contaminated?
Do Chickens Poop, Pee, and Lay Eggs Out of the Same Hole?
Chickens do poop, pee, and lay eggs out of the same hole, yes.
It’s easy to understand how they poop and lay eggs from the same hole. A chicken’s intestine and oviduct both connect to their cloaca, which is their ‘exit hole’.
The interesting part that often comes as a surprise to many is how chickens pee. Or, more accurately, how and why they don’t pee!
Chickens do not have a bladder and they do not pass urine in the same way we do.
Instead, their kidneys remove nitrogen as part of their protein metabolism. This nitrogen is then converted into uric acid, which is passed in a solid form in the same way as their poop.
If you look at chicken poop - and this is true of all birds - you will sometimes see some white stuff in with the poop, this is the uric acid which is essentially their pee.
So, to answer another popular question - chickens pee and poop at the same time from the same hole, yes.
You can find out more about how chickens pee or urinate in this post!
Does It Hurt a Chicken to Lay an Egg?
Laying eggs is completely natural and for the most part, it doesn’t seem to hurt hens.
It’s hard to tell, of course, as much like most animals, hens do not complain and will not always giveaway when something is hurting them.
Some hens clearly struggle more than others, and I’m sure the larger the egg the more likely it is to hurt.
I’ve seen some hens spending longer than others pushing out an egg and making some flustered noises as they strain.
There are also some health issues that can arise, such as hens becoming egg bound, when an egg gets stuck, or eggs cracking internally.
Generally speaking, however, it shouldn’t be painful for a hen to lay an egg.
As chicken owners, we do worry about our girls, but unless you can see you have a hen visibly distressed while pushing out an egg, try not to worry!
Hearing your hen clucking after laying an egg is perfectly normal. So much so that it has a name, it's called the egg song.
I hope I’ve cleared up any confusion you may have had about where chickens lay eggs from, even if you didn’t really want to hear that hens lay eggs from their ‘bums’.
But as I explained, it’s not as simple as saying a hen lays an egg from its bum.
There is certainly nothing gross about it, it’s perfectly natural - don’t let the thought put you off your delicious eggs!
Image credits - Photo by Nick Fewings on Unsplash