Hundreds of pigs were released into one of England's largest tracts of undeveloped land on Monday, the BBC reported. Among them is pannage, which is a historic practice, a season, and a legal right afforded to the pigs' owners. "These clever porkers are nature's very own cleanup crew, keeping our beloved forest safe for all the other animals," the caption explained. In recent years, local officials received reports of pigs being struck by cars during pannage season. Pannage season is expected to end on November 28, but verderers indicated the size of the acorn crop could warrant an extension.