Which animal gives birth to the most babies in the natural world?

The number of offspring an animal can produce depends on many factors, and the subject is more complicated than you might think.

The "champions" of the animal world

There are millions of animal species on our planet, and each species has its own reproductive strategy to suit its environment.

Ocean sunfish can carry up to 300 million eggs (Photo: Getty).

For example, aquatic fish would have an advantage in laying eggs, because they require less energy to release unfertilized eggs, and also have more eggs than animals that give birth to live young.

Ocean sunfish (scientific name: Mola mola) have been found to have up to 300 million eggs at a time in their ovaries.

However, because the eggs are fertilized outside the female's body, once the eggs are released into the ocean, it is impossible to know how many of them will become healthy offspring.

In terms of the number of eggs fertilized at one time, insects will have the upper hand.

Some species of ants, such as the African driver ant (Dorylus wilverthi), can lay 3-4 million eggs in a month. However, the queen will only choose to fertilize a few of these eggs, depending on how many males and females she wants her colony to have.

African driver ants lay up to 3 or 4 million eggs in a month (Photo: Getty).

Among birds, the grey grouse (scientific name: Perdix perdix) is one of the most prolific egg-laying species, with 22 eggs per clutch.

But when it comes to giving birth, seahorses are the champions, capable of giving birth to up to 2,000 young at a time. They incubate and nourish their young through a placenta housed inside a pouch-like organ.

The red-tailed green pit viper (scientific name: Bitis arietans) is the leader among terrestrial vipers . According to Live Science, it can give birth to 156 baby snakes in one pregnancy, and these will develop into healthy individuals.

Why do some species give birth to many, while others give birth to few?

One of the factors that affects litter size is longevity.

Accordingly, animals with short lifespans, or who may not even survive to see their offspring grow up, often have many offspring at once. "Their short lifespans force them to make their mark quickly ," said Kathleen Cole, an ichthyologist at the University of Hawaii.

In contrast, species with exceptionally long lifespans, such as elephants or whales, typically give birth to only one calf at a time.

Elephants only give birth to one calf at a time (Photo: Getty).

Species like bats, meanwhile, need to be light enough to fly and carry their young as they do so. That means bats can usually only care for one young at a time.

Whether an animal lays eggs or gives birth to live young is also an important factor. Young animals require more effort to develop, so species that give birth to live young tend to have fewer offspring.

Another factor is that animals that live in colonies, such as ants, can have more offspring than animals that live alone because they are better protected by the colony.

However, there are always animals that buck the trend. Rabbits and rats, for example, are known for having large litters. Meanwhile, dung beetles, which lay eggs, only lay three eggs at a time.

According to Alex Pyron, an evolutionary biologist at George Washington University (USA), the appearance of such single evolutionary events has always been a mystery, which science has not been able to find an answer to.