How Do Chicks Breathe Inside Eggs?

Have you ever wondered how do chicks breathe inside eggs? Here are a couple of experiments ... or eggsperiments ... which demonstrate the answer.

How Do Chicks Breathe Inside Eggs?

Some Background Information: How Do Chicks Breathe Inside Eggs?

Chicks are just like us ... they breath in oxygen and breath out a waste gas called carbon dioxide. Inside the egg, the chicks need a continued supply of oxygen while at the same time require the carbon dioxide to be removed.

Each chicken eggshell has more than 7,000 pores (tiny little holes in the shell) which can be seen through a magnifying glass. These pores allow oxygen into the egg while providing a route for the carbon dioxide to escape out of the egg.

To allow this process to be seen more clearly, we tried two experiments.

The first involved placing eggs in a solution of dye and leaving for an hour. When cracked open, traces of the dye were visible on the inside of the eggshell, proving that substances can move through the pores of the egg. In this case, the substance was water but for a developing chick, the substances are gases - oxygen and carbon dioxide.

The second experiment involved boiling the eggs.

Eggsperiment One: Food Dye

Materials Needed

Materials Needed

    3 eggs (Note: older eggs will give more marked results than fresher eggs)
    1/4 teaspoon food dye
    1/4 teaspoon detergent
    1.5 cups water
    glass jug

We began by filling a container with 1.5 cups of water.
Add 1/4 teaspoon of detergent
We added 1/4 teaspoon detergent and 1/4 teaspoon food dye.

The solution was well mixed ...
Add the eggs
... and the eggs were carefully added.

The eggs were left to soak for a period of 1 hour.

When the time was up, we carefully removed the eggs and cracked them open. The inside of the eggshells were examined as we looked for evidence that the coloured water has seeped through the pores in the eggshell.
Blue stains on the inside of the eggshell
Blue stains on the inside of the eggshell

If coloured water can seep through the eggshell and leave marks on the inside of the shell, gases can passes through the porous shell in the same manner. This is the answer to the question: how do chicks breathe inside eggs?

(Note: The eggs were disposed of after the experiment and NOT eaten due to the detergent in the water).

Now for the second experiment ...

Eggsperiment Two: Hard Boiled Eggs

The second experiment was based on the same principle as the first except instead of using food dye, we weighed the eggs before and after boiling them. In theory, a hard boiled egg will take on water through the pores of the eggshell and therefore should weigh heavier after being cooked.

Weigh the uncooked eggs

To begin, we weighed the uncooked eggs using scales that can measure in units of 0.1 gram. The two eggs we used weighed 74gms and 76gms.

Next the eggs were boiled for approximately 10 minutes.

Weigh the cooked eggs

Once the eggs were cool enough to handle, they were re-weighed. Our eggs each gained 2 grams which is evidence that the eggs took on water through the pores of their shells.

(Note: these eggs COULD be eaten as no detergent was involved. They made a great lunch for two hungry scientists!)

In conclusion, we figured that chicks do not need scuba exquipment to breathe inside eggs as the shells are porous and gases can pass in and out of the egg as necessary. It seems that the humble egg is a masterpiece of design and technology! If you haven't already seen the experiments focusing on how strong eggs are, have a look at these.

By the way, if you're looking for a humourous story full of eggs, then check out Farmer Blake and Sneaky Snake.

Apps By Stories And Children
You may also like these activities:

The Unbreakable Egg
The Unbreakable Egg
How Strong Are Eggshells
How Strong Are Eggshells
Science Magic: How to Make Floating Eggs
Science Magic: How to Make Floating Eggs
Farmer Blake and Sneaky Snake: A story full of eggs!
Farmer Blake and Sneaky Snake: A story full of eggs!

Return to the Articles List for other children's learning activities or children's book reviews.

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