Did you know that tortoiseshell cats are almost ALWAYS female? That is because the genes that code for fur color are on a cat's X sex chromosome. Female cats have 2 X chromosomes, written as "XX." In contrast, males have 1 X chromosome and 1 Y chromosome, written as "XY." Female cats can have a combination of 2 colors because the fur color gene is on a cat's X chromosome. The first X chromosome carries the orange color gene, whereas the second X chromosome carries the black color gene. This means that the female kitten will have 2 mixed colors of fur! Males are different: males have only one X chromosome because they are XY. So, they can have only one color gene. That is why males will be either only black or orange. There is an exception to this rule, click find out more.
Tortoiseshell cats are known to have a sassy, eccentric, sometimes fiery personalities according to their owners and their vets! However, I have met very calm and sweet tortieseshell cats too! The nickname for tortoiseshell cats is torties.