Gerbil gender is determined by:
* Genitals: Males have a visible scrotum and a larger distance between their anus and genitals than females.
* Body shape: Males tend to have a slightly thicker body than females.
Red eyes in gerbils are a result of:
* Genetics: Some gerbils are born with red eyes, while others have black eyes. This is determined by the genes they inherit from their parents.
It's important to rely on reliable methods for sexing gerbils, such as visual examination of their genitals, rather than relying on eye color.