I may be stupid for looking for any sort of logic in a zombie show but, it drives me crazy that the severed zombie heads keep growling and moaning... Pretty sure you need lungs for that.
Picture Laugh now creature, for in an hour's time you'll be foaming at the month and convulsing like a dirty... monkey? Muahaha!
Picture "Daddy already ran over one thing this morning to get to work. Don't make it two sweetheart."