Bedbugs were discovered in some parts of Thornwood High School, principal Don Holmes said on Thursday.
"I was shocked," a Thornwood parent said. "I was like, 'what?' I opened the email, and I was like, 'bedbugs?'"
The parent was concerned enough to keep her child from going to the South Holland school as it battles a bedbug infestation.
"Bedbugs can be a nuisance," she said. "I've seen notices like that in healthcare facilities, but not in education facilities like high schools."
The school sent a letter to parents earlier this week, announcing the bedbug infestation located inside some areas of the building.
Holmes notified parents of the infestation found near some classrooms, lockers, the nurse's office and cafeteria.
He said the extermination process began right as the bedbugs were discovered.
"We have scheduled a comprehensive extermination process for the entire school building during the weekend of February 3rd. Professional exterminators will apply two treatments to effectively eliminate the infestation," he wrote in part. "Rest assured that the administration is fully committed to the well-being of our students, staff, and the entire school community."
Calvin Preston is a wildlife biologist for Complete Pest Control and Wildlife.
"Bedbugs are extremely common," Preston said. "I mean, you can get bedbugs from just being in any public place."
He said the unwelcome guests can be hard to flee from.
"Bedbugs are just an invasive species that when one person gets them," Preston said. "It's really hard to get away from them, and it's one of those things that people shy away from because no one wants to say 'hey, I have bedbugs."
"Some telltale signs are going to be fecal marks," Preston said. "You might also find bedbug casings or egg casings that you might see."
Thornwood's principal said parents and guardians should alert the school's administration right away if bedbugs are discovered at home.
The school shared information about bedbugs from the Illinois Department of Public Health.