Franklin State health officials have confirmed that a classroom experiment involving owl waste is what caused dozens of students in Franklin to get sick.

Twenty-eight students at Jefferson Elementary School in Franklin had confirmed cases of salmonella poisoning last month. Dozens more children felt sick. The Department of Public Health said the source of the illnesses was owl pellets.

The fifth graders took part in a science experiment, dissecting food pellets regurgitated by owls. Some of the children then ate their snacks from the same tables where the experiments took place. Students told CBS4 that the tables were disinfected before snack time.

The Department of Health says it will issue new guidelines this fall on the dissection of owl pellets in school.