Straight Outta Wikipedia:
'Many taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the "female" or "male".'
Cornu Aspersum (garden snails)
Are all females as well as males.
So how do they ever reproduce?
It's hard to say they're acting loose,
Since none can escape their horny shell.
You might even call it courtship hell.