A Wisconsin middle school has reopened its doors Monday following its early closure on Thursday when a teacher and student were bit by spiders.
Principal Cory Erlandson, at Wilson Middle School in Manitowoc, Wisconsin, confirmed class was back in session on Monday.
The school was closed Thursday and Friday after a teacher and student each reported a spider bite earlier in the week. It was later confirmed that more than 30 yellow sac spiders were found in the building and killed by exterminators.
In a letter sent out to parents, Erlandson said the student's bite area became "itchy and swollen." A teacher also needed medical attention after the bite became swollen, itchy and painful.
"The school has found and eliminated more than 30 spiders in several classrooms and MPSD's buildings and grounds staff are investigating the source," Erlandson said in the letter.
Yellow sac spider bites are not lethal but can be "very painful at the outset and resemble an allergic reaction," according to Pennsylvania State University's Department of Entomology.
No other reports of bites have been made as of Monday.
The full letter sent out to parents last week is included below.