Take yourself a moment and try to think about what will be if there are lots of Zeds in and around houses. Yes, it will take more time to enter, sneak or fight and I am very sure movin quick and battle will make you a lot hungrier.
That means the problem of agressive starving could intensivy itself if that just is possible actually.
This Idea with the can opener needs a complete overhaul or another approach.
Thank you for your time
Best regards