Dog-fouling hotspots will be spray-painted by a council in a bid to get people to clean-up after their pets.
The campaign aims to "remind dog owners of their responsibilities," said Councillor Iain Chubb, of East Devon District Council.
He said it was not graffiti and it would disappear after about two weeks.
The council added it was "targeting a small but persistent group of people who either didn't care or couldn't be bothered" to clean-up.
Mr Chubb, who is the cabinet member for environment, said: "They are the ones putting the rest of us to the trouble of cleaning our shoes, protecting our children from disease carried by dog mess, and even saving other pets walking through the stuff.
"The campaign highlights that you have to pick-up or face prosecution."
He added the mess was not only left by residents but also people travelling to the district.
Irresponsible dog walkers face fines of up to £1,000.