DULUTH, Minn. - A Duluth elementary school is closing for the summer due to a rat infestation, according to the district.

The Duluth School District sent out a press release on Wednesday saying that Congdon Elementary School and its grounds will be closed while they work to remove a "population of rats" from the footing and foundation drainage system under the gym.

The district says the rats have been seen entering the drainage system and there are burrow entrances at the back of the building. Pest control workers are trapping five a day, the district reports.

The district facilities manager, Dave Spooner, said they first removed food sources that could attract the rats. Then Spooner said they will begin to use the "least toxic method" of pesticide bait boxes set outside near the burrow entrances.

"Our goal is to definitely have these rats eradicated before the school starts in the fall," Guardian Pest Solutions Entomologist Jamie Kopco said.

"We’re working to remove them from the burrows created in the hillside and beneath the gym addition before they can get into the building itself,” Spooner said. “Having the building and grounds unoccupied will allow us the flexibility to take steps necessary to make that happen."

Spooner said they will use signs to alert the neighborhood that those boxes are being used.