Which animal has the highest number of offspring in a single litter?

When it comes to having large litters, there are a few contenders in the animal kingdom. However, the title of the animal with the highest number of offspring in a single litter goes to the armadillo. The nine-banded armadillo, which is native to the Americas, typically gives birth to litters of four identical quadruplets. This means that each litter contains a total of 16 offspring!

The reason for the armadillo's unusually high litter size has to do with its reproductive biology. Armadillos are unique in that they always give birth to identical quadruplets, meaning that the fertilized egg splits into four embryos early on in development. This is known as polyembryony, and it's what allows the armadillo to have such large litters. It's also worth noting that armadillos have the ability to delay implantation of the fertilized egg, which means that they can time their pregnancies to coincide with favorable environmental conditions.