Worms have a clitellum which is a whitish band near their anterior (head) end. It has both male and female reproductive organs. When mating, two worms join with heads pointing in opposite directions. Sperm passes from one worm to the other and stores in sacs. A cocoon forms on each worm’s clitellum. They back out of the narrowing cocoons, leaving them behind. Cocoons can have from 1-5 worms each, and will go dormant for years if hatching conditions are not right.