Which animal gives birth to the most children?

The "champions" of the animal world

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

For example, fish that live in water require less energy to release unfertilized eggs, so they have an advantage in giving birth to live young and also have more eggs than animals that give birth to live young.

Ocean sunfish (Mola mola) have up to 300 million eggs in their ovaries at a time. But because the eggs are fertilized outside the female's body, it's impossible to know how many of them will become healthy offspring when they're released into the ocean.

In terms of the number of eggs fertilized at one time, the advantage belongs to insects.

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

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

But seahorses are the champions when it comes to giving birth. They can give birth to up to 2,000 babies at a time.

Among terrestrial vipers, the red-tailed pit viper (scientific name: Bitis arietans) tops the list, being able to 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?

Lifespan is one factor that influences litter size. Short-lived animals tend to have many young at once. Their short lifespans force them to make their mark quickly, says 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.

Species like bats carry their young when they fly, so they can usually only care for one young at a time.

Another important factor is whether to give birth or lay eggs. Species that give birth to live young will usually have fewer offspring because the young require more effort to develop.

Another factor is that animals that live in herds are better protected and can have more offspring than animals that live alone.

However, there are always animals that buck the trend, such as rabbits and mice, which are famous for their large litters, and dung beetles, which lay eggs but only three at a time. Such singular evolutionary events remain a mystery that science is still trying to solve.