Chinese park officials are fitting steel spikes on benches in a bid to stop people from hogging them.
If visitors to the Yantai Park in Shangdong province, eastern China, sit too long on the seat without paying at the nearby meter the spikes will shoot up through the bench.
Although they can't cause any serious harm, they are long enough to stop people sitting comfortably.
Parks in China suffer from severe overcrowding at weekends when millions of people try to escape the country's cities.
One official said: "We have to make sure the facilities are shared out evenly and this seems like a fair way to stop people grabbing a bench at dawn and staying there all day."