Mike Armour, director of operations for the Rock Hill school district, said the most recent bat sighting was Friday around 3 p.m. In all, about 40 bats have been spotted inside the school in the past three weeks, he said.
"We keep thinking that we're getting rid of them and they're going away, and they keep coming out of the ceiling," Armour said.
To battle the bat problem, district staff use a large vacuum to suck up the bats. Then, the animals are set free outside.
Staff also are patching up any holes that would allow bats to go in and out of the building. Sometimes, those spots can be found by looking for bats flying at dusk, Armour said.
District spokeswoman Elaine Baker said other schools have had bats before, and they do not pose a danger to the students or staff.
"We hope not to have the problem very much longer," she said. "This is just something that occurs in some of our schools, just like it occurs in many homes, and we have to do what we've been advised to do. Our people have been working on this expeditiously to try to get the situation resolved."
Because the bats have been seen in the cafeteria, Armour said operations staff have been careful to clean and sanitize the area. Most of the bats in the cafeteria have been seen flying, not hanging, he said.
An S.C. Department of Environmental and Health Control inspector visited the school Friday, but did not see any bats, DHEC spokesman Adam Myrick said.
At the request of DHEC, a wildlife specialty company will inspect the school today and possibly make recommendations for what to do.
Roger Bradley, chief animal control officer for York County, said bats venture inside looking for shelter.
"If they can get in and out and have that shelter, that's what they're hunting," he said.