Why are hares associated with the moon? Hares are fundamentally nocturnal. Nighttime was once a very dangerous place and the moon was once believed to actually cause madness, (hence luna / lunacy). Knowing that the hare regularly went about its business under a mania-inducing moon, it was assumed that this was the cause for their ‘madness’ during spring. The mad March hare was indeed seen as ‘moon-struck’.