I keep my grain (in bins) in an old chest freezer for this exact reason.

Unless you have thumbs, you can't get into it.

My old appy once ate 1/2 bag of Cob and was completely fine. (before I got him).

http://images.yuku.com/image/gif/65d269e3f5844c51cf256773072659fc11e4f64a.gif