Treats and prizes can help reinforce good behavior for your students and show less-well behaved students a role model. Award prizes for perfect attendance, good behavior, or just for extra-helpful students. While bribery is never good, awarding good behavior tells students that their actions are noticed and holds them accountable for it. Encourage students to study for the test by awarding them with treats once it's over.
With allergies becoming a growing concern for school administrators, some parents would prefer that you didn't award food as a prize, finding small little trinkets and prizes is a great alternative! Personalized favors for good behavior and mindfulness will have the same effect without encouraging childhood obesity.