'I thought snakes laid eggs': Boa birth video leaves internet scratching its head

An incredible video of a snake giving birth has left the Internet scratching its head.

Facebook page Reptile Collective posted a video of a sand boa giving birth.

The snake slides out, pink, smooth and shining from its mother's tail.

Amazingly, it instantly opens its mouth before lying calmly next to what appears to be another newborn sibling.

The baby snake takes its first breath. Source: Facebook

A trail of a yolk-like substance sticks to the snake as it lays.

A few seconds later another serpent begins to protrude from its mother, who begins giving birth again.

The video has more than 9.8million views, 75,000 shares and 22,000 comments.

But there is one question confusing the internet: “Don’t all snakes lay eggs?”

According to the San Diego Zoo, the Erycinae, commonly known as boas, are generally ovoviviparous meaning they give birth to live young instead of laying eggs.

“The young are attached to a yolk sac and surrounded by a clear membrane, not a shell, as they develop in their mother’s body,” according to a description of the boa on the zoo’s website.

“When the young are ready to be born, they are pushed out through an opening called the cloaca.

“They are still surrounded by a clear, protective membrane that they must push through.”

The mother gives birth again just moments later. Source: Facebook

However, the Calabar python, the Arabian sand boa and the West African sand boa lay eggs.

There are currently 15 species of boa recognised.

According to National Geographic, the rarest boa on earth, the Cropan’s boa, was rediscovered in Atlantic Forest, outside Sao Paulo, Brazil in February.

It was thought to have been dead for 64 years.