Teachers are excited to welcome children back to school in the fall, but the pests that sometimes hitch a ride to school on students or their backpacks have cast an unpleasant pall on the start of the school year. Teachers and students have gotten used to the weekly head lice checks and lectures about hat sharing. But the resurgence of bed bugs has added an unwelcome tension to the start of the school year and made teachers — and students — hyper aware of creepy crawlies in their classrooms.

Because bed bugs are not known to transmit disease, they are classified as nuisance pests. But these tiny insects invoke a huge creep factor. Largely nocturnal, bed bugs creep into their human victims’ beds at night to feed on their blood. Unlike head lice, bed bugs do not live on the human body. Between meals they crawl away to hide in nearby cracks and crevices.

Bed bugs are adept hitchhikers and frequently arrive in schools hidden in the backpacks or clothing of children who live in infested homes. A bed bug sighting can induce panic as it did at Newark High School in Ohio recently when bed bugs were spotted crawling on a student’s backpack. Students were phoning their parents in panic and more than 100 worried parents pulled their children from classes.

Next time: What to do when bed bugs come home from school