Which animal will always give birth to identical quadruplets?

Which animal will always give birth to identical quadruplets?

The correct answer is Armadillo — specifically the nine-banded armadillo (Dasypus novemcinctus). This unique mammal is the only animal known to always give birth to identical quadruplets. Each litter originates from a single fertilized egg that splits into four separate embryos, resulting in four genetically identical offspring.

The nine-banded armadillo’s reproductive process is fascinating to scientists. After fertilization, the egg remains dormant for up to four months before implanting in the uterus — a phenomenon known as delayed implantation. Once the embryos begin to develop, they divide evenly into four, ensuring the birth of identical quadruplets every time.

Found throughout the southern United States, Central America, and South America, armadillos are recognized by their armor-like shell made of bony plates. Their cloning-like reproduction makes them particularly valuable in genetic and medical research — including studies on diseases like leprosy, since they are one of the few non-human animals susceptible to the bacterium that causes it.

Fun fact: Because each litter is genetically identical, armadillo quadruplets have been used in scientific studies to examine nature vs. nurture — since differences among the siblings are due entirely to environment, not genetics.