Science, Tech, Math › Animals & Nature How to Sex Pet Millipedes Learn How to Tell the Difference Between Male and Female Millipedes Share Flipboard Email Print Animals & Nature Insects Basics Behavior & Communication Ants. Bees, & Wasps Beetles Butterflies & Moths Spiders Ticks & Mites True Bugs, Aphids, Cicadas, and Hoppers Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Marine Life Forestry Dinosaurs Evolution View More By Debbie Hadley Entomology Expert B.A., Political Science, Rutgers University Debbie Hadley is a science educator with 25 years of experience who has written on science topics for over a decade. our editorial process Debbie Hadley Updated March 06, 2017 Because millipedes breed easily in captivity, it's a good idea to know the gender of any millipedes you keep together in one terrarium. If you don't want a large number of millipedes to care for, choose millipedes of just one gender, or don't mix males and females together. It's fairly easy to tell the difference, if you know how to sex pet millipedes. Male millipedes have gonopods in place of their legs, usually on their 7th body segment from the head. The gonopods are modified legs used for transferring the spermatophore to the female. In some millipede species, the gonopods are visible, while in others they are hidden. In either case, you should be able to identify a millipede as male by examining the underside of the 7th segment. For species in which the male gonopods are visible, you will see two small stumps in place of a pair of legs. If the gonopods are hidden, you should notice a gap where the legs would be, as compared to any other segment on the body. In females, the 7th segment will look just like all the others, with two pairs of legs. For more on keeping millipedes as pets, read my Guide to Caring for Pet Millipedes.