Halloween pranks might already have begun at NIU.

Two people clad in black ninja outfits were spotted in the parking lots between and near Grant and Douglas residence halls early Monday morning, police said.

University Police received two reports of the ninjas acting suspiciously in the parking lots, but when they arrived on the scene, they could not find the warriors, UP Lt. Ron Williams said.

No damage was reported in either parking lot.

“They’re just trying out their costumes to see how well they go across,” he said.

Williams said there probably will be a lot of pranks with Halloween only two weeks away.

UPs expect to find pumpkins smashed on the street and houses draped with toilet paper during the next few weeks, he said. The greek row area already was decorated with toilet paper, he said.

“This is just a normal kid-type thing, though you’d expect it more of younger kids than college students,” he said.