How to tell the difference between a girl and boy kitten?

One way to tell the difference between a girl and boy kitten is by looking at their genitalia. Male kittens have a visible scrotum and penis, while female kittens have a small, slit-like opening called a vulva. Another way to determine the gender is by looking at the distance between the anus and genital opening - it is typically shorter in females and longer in males.