The state Department of Public Health is investigating why at least a handful of students have contracted salmonella bacterial infections,and is exploring a possible link to a fifth-grade science experiment.

While the DPH has ruled out cafeteria food in Jefferson Elementary School as the reason at least five fifth-graders and one first-grader have become ill, state officials are not discounting the role of the experiment in which students dissected owl pellets, or excrement.

"I certainly don’t want to go out on a limb and say (owl pellets) were the cause," DPH spokesman Donna Rheaume said. "It’s way too early to speculate. We’re looking at everything the students had in common."

What five of the six confirmed cases did have in common, school officials and parents confirmed, was the students’ participation in the experiment over the last few weeks. DPH visited the school Friday and yesterday and gathered evidence, including owl pellets used in the fifth-grade experiments. The school has been sanitized.