I keep my chicken feed (in the sack it comes in) inside a closed galvanized garbage can in my utility room (on carport). Last week I noticed that my 3 hens weren't eating the feed I put out for them, and also that when I took the lid off the storage can, it smelled terrible. My first thought was that a rat had somehow gotten into the can, it smelled that bad. But of course the can didn't have any pests in it, just the sack of layer pellets. I only have 3 hens, so a 50-pound sack lasts a good while. Did it just get too old, or did the heat (we're in the 90's here and very humid) ruin the feed?