The ‘microworm’ with the weirdest sex life on the planet: Researchers find males have no penis, and instead massage sperm from a sack on female’s bodies But males of this species lacks a penis and instead massage a sack containing sperm above the female’s genital opening, which enters the female A new species of microscopic nematode worm whose males have no penis has been discovered be researchers in southern Spain. The male will instead massage a sack containing sperm above the female’s genital opening, which enters the female’s genital tract.