It's a traditional family pursuit that has entertained children and nature lovers for generations.
But now people caught daring to feed the ducks outside a designated area in Ely could be fined up to £2,500.
East Cambs District Council officers now have the power to fine anyone caught feeding the city's colourful waterfowl population anywhere other than on the water.
Earlier this year, the council announced it was creating designated duck feeding areas along the river's edge in Waterside in a bid to encourage the birds off land and on to the water.
Now a warning sign has been fixed to a lamppost in front of the city's most popular duck feeding spot on Waterside - on the piece of land opposite Peacocks Tearooms.
The council says it is trying to stop people feeding the birds on land to prevent them churning up and wearing the grass down.
The signs down by the riverside are the maximum penalty for persistent and consistent failure to follow the rules and could only be awarded by a court.