A sea hare is a hermaphrodite, i.e. both male and female at the same time. How does it mate?

Explanation

Like all opistobranch mollusks, sea hares are hermaphroditic. Their mating ritual is really quite strange: sea hares have discovered that the most efficient way to mate is in a chain consisting of several animals. The sea hare in front takes on the role of a female for the sea hare behind. Sometimes they form a giant circle, where all mate happily all day long.