Learned a trick from my grandfather a long time ago before he passed. He would wrap up some ice cubes in tin foil and put them near the candy to hand out. He'd put them in the bags of "kids" that were 13+, didn't say Trick or Treat or had mustaches.
Tradition lives on. Enjoy the wet bag of candy.
Anyone else play any "tricks" on kids that shouldn't be trick or treating?