Kids love climbing and playing at Fort Barnard Park in south Arlington, VA, but now they have to watch where they step.

Some parents are disgusted after learning a “serial pooper” is targeting the playground.

“I have three kids, one is a cancer survivor. You run into something like that?” Andy Delafield, who takes his kids to Fort Barnard Park, said. “Oh my God. Just … ugh. Who would be sick enough to do something like that?”

Arlington County Parks and recreation officials say human poop has been found about four or five times in the last few months.

Whoever is responsible is covering the poop with a shirt or jacket.

Park workers believe it happens after hours in the dark. Each time it is reported, workers clean it up and disinfect the area.