A litter of five calico babies came to the Cat House on the Kings in Parlier, California early September. Soon they discovered something quite unique about this litter. Two out of the five kittens are male calicos.

Meet the calico clan.

"We took in a litter of 5 calico kittens and two were boys," Harvie Schreiber of the Cat House on the Kings told Love Meow.

Having a male calico is one out of 3,000 chance. Now they found two in the same litter, the odds of that is simply astounding.

Just like humans, cats have two sex chromosomes that determine their gender. Female kitties have only X chromosomes while male cats have both X and Y chromosomes.

Here's one of the two boys.

A calico or tortoiseshell must have two X chromosomes which means the kitty is going to be female 99.99% of time.

It's very rare to see a male calico, but even more unique when there are two from the same litter.

This little boy share the same markings as his calico sisters.

One of their three sisters.

The calico pattern exists in male cats is because the cat has an extra X-chromosome: two X, one Y (male). In humans, this condition is known as Klinefelter Syndrome.

Calico girl from the litter of five.

They don't have much info on their cat mom or dad, but the kittens certainly share a very strong calico gene.

Each of the five calicos has their unique personality.

Little calico princess.

"These kittens are very rare and the boys have been adopted together."

Watch them in this cute video:

Two calico sisters are still looking for their forever homes. You can visit the Cat House on the Kings for more info about this adorable calico family and other kitties that are also waiting for their loving homes. Follow the Cat House on the Kings on Facebook.

Related story: Man Captures Moments of Him Being Chosen by Calico Stray He Met in Cornfield