Principal Donna Bairrington sent a letter home with students who ride that particular bus, letting parents know about Wednesday morning's incident.
School spokesman Chuck Glenewinkel declined to provide details on the student who shared the bullets or what discipline the youngster faces.
Administration officials determined the child did not intend to harm others and the incident, discovered when a bullet fell from a student's pocket at school, did not involve a weapon.
Glenewinkel says no bullets were found on the bus. Four bullets were recovered from students, while another one turned up in a trash can.
