Animals that lay eggs – complete list of egg-laying animals

Looking for a list of animals that lay eggs? Well, you’ve come to the right place. In this article we will tell you every kind of animal that lays eggs, divided into 5 groups, as well as answer some related questions. Lastly, we’ll list some interesting facts about eggs, that we bet you haven’t heard of!

Let’s get straight to it:

List of animals that lay eggs

In general, a list of animals that lay eggs can be divided into 5 groups: birds, fish, reptiles, amphibians, and insects. There are exceptions to this list, as some animals in these groups reproduce in other ways and a few animals that are not covered in these groups do lay eggs. 

Birds

All birds lay eggs! Every kind, from eagles to hummingbirds share this trait. A group of eggs in a nest is called a clutch. Unfortunately for the birds, many animals feed on their eggs. For some animals, eggs actually make up the majority of their food intake. Birds react differently to “egg-theft”, some quickly lay another egg to replace the stolen one, while other birds do nothing in response. Birds are classified into two categories based on this: Determinate layers (number of eggs laid is predetermined) and indeterminate layers (these birds react to the loss of eggs by laying another).

There are lots of animals that lay eggs that aren’t birds though:

Fish

Fish lay eggs all the time! Actually, some fish can lay up to 6 million eggs at a time. While fish use different tactics for reproduction, the most common one is called oviparity. This involves the female laying underdeveloped eggs in mass, and having the male fish inseminating them outside of the mother’s body. Not all fish lay eggs though, some are so-called “livebearers”. This means that they are internally inseminated, and the mother fish will carry her babies within her until they are big enough to survive on their own.

Fish consider eggs a healthy and tasty snack. They won’t hesitate to eat their fish buddies eggs, or even their own in some cases.

Reptiles

Some reptile species give birth to live offspring, but most reptiles lay eggs. For many reptile species, their eggs are softer than what we are normally used to. Their shells are not as hard as, for example, a chicken egg. Reptile eggs are symmetrical, meaning they are round or pill-shaped instead of “egg-shaped”.

The gender of the developing embryo is partially determined by the surrounding temperature. A colder climate increases the chances of male offspring, and vice versa.

While some reptiles ferociously guard their eggs, others leave them to hatch on their own. This behavior varies between reptile species.

Amphibians

Amphibians, such as frogs and salamanders, mostly lay their eggs in water. This is because the eggs lack a protective shell, so they likely wouldn’t fare well on land. Amphibian eggs are made up of a gooey sphere with a small embryo inside. The offspring, called tadpoles or larvae, live in the water during their first time in life, breathing through gills

Insects

 Insect eggs come in many different shapes and sizes. Some are gooey, similar to amphibian eggs, and some are rigid, more akin to a super small bird egg. Some insects can guard their eggs by producing a glue-like substance. They use the substance to cover the eggs, protecting them from external threats.

Other animals that lay eggs

Some egg-laying animals do not fit into these groups above though. There are 5 mammals that reproduce through laying eggs: Duck-Billed Platypus, the eastern and western Long-Beaked Echidna, and the Long- & Short-Beaked Echidna. 

These animals are called Monotremes, and are native to Australia and New Guinea.

Why do some animals lay eggs?

The reason that some animals lay eggs is simply because it is more beneficial for them, compared to birthing live offspring. This also means that they can produce more children since the growth doesn’t take place within the mother’s body. An example is birds, who would have a hard time flying if they carried they offspring inside their body. Other animals live in environments that are dangerous to newborns. for this reason, evolution has decided that they should grow their offspring internally. Animals such as rodents do not lay eggs, since it would not be beneficial for them.

Animals that lay eggs tend to produce more offspring than animals who birth live offspring. An example is cod fish, which can produce up to 6,000 eggs per spawn.

Did you know? Fascinating facts about eggs

1. The biggest egg ever laid in the world was by an ostrich in the Swedish city Borlänge. It weighed 2,5 kg (~5 pounds), equal to about 42 regular chicken eggs.
2. On the other hand, the world’s smallest egg only weighed half a gram and was laid by a Colibri. 
3. The average US citizen eats about 300 eggs per year, or slightly less than 1 egg per day, a study showed. Egg consumption has gone up in the last few years.
4. It takes about 25 hours for a hen to develop an egg. They are also the terrestrial species that can produce the most amount of eggs. About one egg per day.
5. Only 1 in 20,000 eggs we eat contain salmonella bacteria. In other words, the chance of contracting the disease from eggs is really low.
6. Even though a lot of animals we know birth live offspring, more than 99% of the animals in the world do lay eggs.
7. Think chicken eggs are the only ones you can eat? Incorrect! Many different eggs are edible: goose, ostrich, duck, and even crocodile eggs are edible and healthy.
8. The biggest egg ever laid by a hen contained two shells, two yokes, and weighed about 1 lb, almost 8 times more than a regular egg. In general, 

Conclusion

So, in this post, we’ve examined which animals lay eggs and learned that only 5 groups of animals do. We’ve also looked at why animals lay eggs, as well as covered some of the most interesting facts regarding the subject. All in all, we hope that you’ve learned something from this article. If nothing else, then we hope it was a fun subject to read about!