An egg of the chicken has a very tough outer shell. It’s used to protect the chick until they are able to hatch. Since the eggshell is quite hard, you may wonder how would a chick is able to break through it. Luckily for them, they have something known as an “egg tooth”.
What is an egg tooth? An egg tooth is a sharp projection that is found on the front of the beak of the chick when they hatch. This allows the chick to penetrate the eggshell and breakthrough it.
Why Do Chicks Have an Egg Tooth?
An egg tooth is an important feature that every chick has when they hatch. Without it, they won’t be able to break through the eggshell.
When the chick is still in its egg, the claws and beak are still weak. It won’t be strong enough to break through an eggshell.
To help them break the eggshell, the chick will use the “egg tooth” and peck at the eggshell until it’s cracked.
Due to the toughness of the eggshell, chicks could spend hours pecking at it until they are able to get out.
Not only do chicks have an egg tooth, but other egg-laying mammals as well. A lot of bird species, lizards, and snakes have them when they are about to hatch.
Is An Egg Tooth A Real Tooth?
Yes, an egg tooth that the chick has is a real tooth. Chicks only have one egg tooth when they are still in the eggshell.
However, a few species, such as gecko, actually have two egg teeth.
Chicks don’t need more than two egg teeth. They are able to break their egg with just one egg tooth, as they take their time to peck at it for several days.
How Do Chickens Break out of Their Eggs?
A chick will usually stay in the eggshell for a total of 21 days. This is the average time for the chick to develop and be able to survive outside the eggshell.
However, some chicks will hatch a day or so earlier. Others may hatch a couple of days after the 21-day period. Usually, if this happens, it isn’t a concern.
About 17 days, the chick will start to use its egg tooth to break the air cell inside the egg. Doing so will help release additional oxygen and allows the chick to start breathing air.
A couple of days later, the chick will “pip” their shell. Pipping simply means they have made the first crack in the eggshell. Doing so will cause more oxygen to stream into the egg.
The chick will continue to pip several more times, but they start to “zip” their shell. Zip means the chick has broken the eggs through, which causes a line to form around the egg.
As the zip becomes longer, the chick will start to use its head to break out of the egg.
The video below is a chick hatching using its egg tooth to breakthrough:
What Happens to the Egg Tooth After The Chick Is Out?
After the chicks have broken free from the eggshells, the egg tooth will stay intact. They will no longer use it and therefore, after about 3-4 days, it will fall off.
Do Ducks Have an Egg Tooth?
Just like chickens, ducks do have an egg tooth as well. It’s small and sharp, which is located at the tip of their beaks. They will peck at the egg until they make a small hole, which they will then force themselves out of the shell.
Do Turtles Have an Egg Tooth?
A turtle does have an egg tooth as well. On the turtle, it’s known as a caruncle. Similar to chicks, they use their caruncle to break through their eggshell. It’s located at the top of their jaw. Once the turtle hatch out of the egg, it will take several months for it to fall off.
For baby chicks, their egg tooth is an important tool. Without it, it will be nearly impossible for them to break out of their eggshell. The egg tooth is only temporary and will fall off its beak within a couple of days.