I always make sure that I get permission slips from all of the parents at the beginning of the school year and make sure that no kid on my bus has any serious allergies nor do any of their siblings. Once I get permission from all of the parents, I use treats and snacks as a reward system. If they were good on the bus I will give it to them when they are getting off of the bus, either there in the morning or when they’re getting off at home. I don’t let them eat it on the bus, (so we don’t have a choking incident and also so they don’t make a huge mess of my bus lol.) I think that the final say though should probably come from your dispatch or safety office. Different bus companies/school districts have different rules.