It all started in 1878, in the lake Hjälmaren, where over-fishing of crayfish threatened the survival of the species. A ban was imposed, which later spread to other parts of Sweden. It was not permitted to catch crayfish from the 1 November until the 7 August, which meant that the 8 August became the first day of the crayfish season. Even though the ban has long since been removed, Swedish people continue to start catching crayfish – and hold crayfish parties! – on 8 August every year. The date was probably chosen because crayfish shed their shells two to three times during the summer as they grow in size, during which they hide under stones and are extremely difficult to catch.