Sexing Mongolian Gerbils

It is important to be aware of the sex of your gerbils, especially if introducing new pups. Although a reputable breeder or rescue should be able to do this confidently, it is worthwhile taking a moment to accustom yourself to this guide to sexing gerbils to help you identify the differences yourself. It also means that if a mistake has been made you will pick up on it quickly and you can be sure your pet gerbils won't have unexpected litters!

If you have any concerns or notice any unusual behaviour then it is always worth checking.

Female gerbils are called Sows and male gerbils are called Boars.

• Females: Have more obvious nipples, this is best used at 2 weeks before they become obscured by hair. It is not a completely reliable method and should be used as a guide only.

• Males: have a large bulge at the base of their tail, usually visible from 4 weeks and obviously by 6.
• Males: have a much larger scent gland than females. However dominant mongolian gerbils will have the biggest scent glad so in an all female group the dominant girl would still have a bigger scent gland.
• Males: are generally larger than females, but this can be influenced by many other factors.

Behaviour can also play an important part - as although same-sex mounting is common when gerbils mate there tends to be a more concentrated effort, usually in the evenings, with a prolonged period of chasing. Drumming can be a sign of sexual excitement so may well accompany this.

Main method

The main distinction that you should be aware of is one common to most rodents - in that the distance between urinary and anal openings is much smaller in females. This can be used from 3 weeks of age and is the best indication of a gerbils' gender.

The example photos on the right clearly show the male gerbil with a visible bulge at the base of his tail and when you compare to the female gerbil you can see that the distance between his urinary and anal opening is much greater.