CHARLESTON, S.C. (AP) — The bedbugs are back at a South Carolina fire station one month after an outbreak at four stations.

The Charleston Fire Department said in a news release Wednesday that bedbugs have been found at one of the stations that had problems earlier this year.

Firefighters are being moved to another station about 3 miles (5 kilometers) away.

Charleston spokesman Jack O’Toole said the bugs were found on a covered mattress in the station’s dorm. A pest-sniffing dog determined the infiltration was limited to one area of one room.

Interim Fire Chief John Tippett says the department has a set of pest control procedures after the earlier outbreak.

The last infestation lasted a month. Officials eventually used large propane tanks to heat the stations to rid them of bugs.