We wanted to store our chicken food and treats outside for easier access. However, without proper storage you will likely attract pests and you run the risk of the food spoiling from moisture.
I purchased two 50 lb. Vittles Vaults online. They are moisture and pest proof, which allows us to store all of our supplies right in the coop. They are a little spendy but well worth the investment.
Thanks so much for this hint. I keep parrots in 2 large aviaries & have the same problem with my seed. I have been keeping it stored in drums in the garage - but this idea appeals to me.