CLARK CO., Ohio -- Imagine arriving at your son or daughter's high school to drop them off and being met by a drug-sniffing dog.

That is exactly what happened to some parents at Northwestern High School in Clark County Thursday morning. "I thought, what the heck's going on," said Mildred Creachbaum.

She later found out that it was a surprise drug sweep of the entire high school and middle school.

Everything from the parking lot to the lockers were swept for drugs. Lorie Swafford, principal of the high school said, "I think it's really important for the community to see we're on top of drug issues. This was a surprise and no one in the district knew but the superintendent and me."

Drug-sniffing dogs also checked out student book bags and the bleachers in the gym, but turned up nothing.

Last year, the drug dogs did make a find in the school parking lot and an arrest was made.

This year, police said the sweep was a reminder that authorities are taking illegal drugs seriously.

Sgt. Michael Stitzel of the German Township Police Department said, "We try to do random checks throughout the school year. Not so much that we suspect that there's drugs in school, rather we're trying to just be proactive and on a preventative maintenance."

The middle and high schools were locked down for awhile during the search.

Parents like Mildred Creachbaum supported the search, saying "Kids today experiment with different things and hopefully, if they have anything, their parents will get them help."

The drug dogs were proved by the State Highway Patrol.