Cats may bite, and geese may have barbed penises, but one newly described hermaphroditic sea slug has taken violent animal sex to a new level by stabbing its mates in the head. 1, is a small sea slug found off the northeast coast of Australia. A simultaneous hermaphrodite, it has both male and female reproductive organs that it uses simultaneously during sex. This stabbing behavior, known as traumatic secretion transfer, is fairly common amongst hermaphroditic sea slugs, and does not actually traumatize the slug â the term trauma refers to the Greek translation as "wound." The behavior is well documented, but still not very well understood.