The collective noun for a gathering of Hares is a Drove. I have also heard a Down of Hares used too, although I believe in the states a Husk of Hares is more appropriate.
On moonlit evenings and bright short days it is now possible to see Droves of Hares. They make fascinating watching. Contra to popular belief they box for much of the year. They breed for much of the year and so the pre-mating ceremony of boxing when the female tries to fend off the attentions of the male also takes place throughout most months. Perhaps it is the snow covered fields and/or short crops that make it more obvious during spring. It may also be the short days forcing this normally nocturnal activity into daylight hours that make boxing Hares easier to see
One or two were chasing around within a group of around ten opposite Falcon Cottage at the weekend but none came close enough to offer a real photo opportunity.
Letter From Norfolk 