Expression "mad as a March hare", is possible, familiar not to all. It has appeared in England in the 15th century. The word "madman" can be applied to behavior which from usually quiet and peaceful suddenly becomes strange, violent, sharp. Quite so hares begin to behave during the reproduction period (which in Europe happens usually in March). At the beginning of a season, yet not persons interested to copulate females often use forepaws to reject too persistent males. In olden days, such behavior mistakenly was accepted to fight of males for an arrangement of females.
Conclusion: this statement — the truth.