I finally solved the mystery of who's been stealing the 'prop' candy. I placed a small glass vase into a larger one, and filled the space in between with conversation hearts. Slowly, I've noticed the candy level has been going down. I spoke to the boys about it. (I even went so far as to threaten to sprinkle hot pepper on the candy.) As it turns out, the kids aren't the only ones who've been picking...
"If I just play it cool... maybe she won't notice me."
"Okay, the coast is clear... this may be my only chance."
"OMG! I think I'm actually gonna get some candy."
" Wait! Is she looking? I'll pretend I'm just smelling the flowers."
"That's it... I can't wait any longer!"