Exterminators will treat the entirety of Mars High School over the weekend after another bed bug was found in the school — the second sighting this week.

On Monday, two bed bugs were found in the school’s Classroom 140, a room developed to resemble an apartment where students learn everyday living skills, according to Superintendent Wesley Shipley. On Friday, a third bug was found “several hundred feet” from the initial sighting, Shipley said.

“All told, there were three bugs found in the entire building,” Shipley said.

The district hired Terminix to handle a schoolwide bed bug treatment, Shipley said. The treatment will cost about $17,000, he said.

“It’s not a cheap proposition,” Shipley said. “It’s expensive, but necessary.”

District officials believe the bugs were brought in on student clothing. The district isn’t sharing any specifics about which students might be involved or the specific preventive steps being taken to ensure more bugs aren’t being brought into the building out of respect to family and student privacy.

The treatment process will be a combination of two methods. The first is a widespread, carbon-dioxide gas that freezes the bugs, killing them, and allowing them to be vacuumed out for disposal. Exterminators will also employ a targeted spray in crevices and along walls in likely hiding spots. Treatment was planned to occur as quickly as possible, to allow drying and fumigating over the weekend.

The school closed immediately after class Friday for the process to begin.

Shipley said they expect to be fully clean and open for class on Monday. He said the treatment processes they’re using don’t leave a residue or smell, and won’t be harmful to students.

Cheri, a mother of a student in the school, spoke to the Eagle about the bed bugs on the condition that her last name not be used, so as to protect her child’s identity.

Cheri said her daughter’s class had found a bug in their geometry classroom, which is on the second floor of the building. Monday’s sighting was on the building’s first floor.

She said her daughter’s class, with the aid of her daughter’s teacher, had used the internet in class to identify the insect as a bed bug.

Cheri was troubled that the district had waited until Friday to address the problem.

“They have been carried this week from one class to another class,” Cheri said. “They had a large assembly the other day.”

She wished the school had quashed the problem before the bugs had the opportunity to spread.

“They should have closed it down and did what they had to do so this didn’t affect hundreds of other people,” Cheri said.

In a letter to parents, Shipley recommended that families place any clothing or school items in sealed plastic bags outside of their homes. The items should be washed and dried on a high heat for at least 30 minutes to kill the bugs.

Bed bugs are small, flat insects and are roughly the size of Abraham Lincoln’s head on a penny.

Bed bug bites can appear either randomly over the body or in straight lines of bites, the Centers for Disease Control reports. The bite marks are red and appear similar to a flea or mosquito bite.