I have 4 chickens and so far have stored all their supplies in my house near the back door - but come winter, I would like to have the food (and shavings) stored out in the yard close to the coop. I understand that a galvenized can is no chew-through-able by potential chicken-feed thieves, but can they be secured? A neighbor seems to keep her food in a rubbermaid tote out near her chickens but I fear that a squirrel family could easilt gnaw a hole in plastic. What do people do if they don't have storage inside their coop? Thanks in advance for any help or suggestions!!