A woman watches as Morris Dancers celebrate in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

A reveller walks through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

A reveller in fancy dress walks through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Morris Dancers celebrate beside The Bridge of Sighs in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Morris Dancers celebrate beside the Radcliffe Camera in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

A Morris Dancer dressed as a tree walks past the Bodleian Library as they celebrate in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Students and revellers dance through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Revellers dance through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Revellers dance through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Morris Dancers celebrate beside The Bridge of Sighs in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Morris Dancers drink from pewter tankards as they celebrate beside Radcliffe Camera in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Students and revellers dance through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. The May Day Morris celebration is a traditional rite thought to be connected to changing seasons and fertility. (Photo by Darren Staples/Reuters)

Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

A boy dances with Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

Leicester Morrismen dance during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

Leicester Morrismen rest between dances during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)

A Leicester Morrisman fills his tankard with beer between dances during May Day celebrations at Bradgate Park in Newtown Linford, Britain May 1, 2015. (Photo by Darren Staples/Reuters)