The delivery is made entirely of the black and white sunflower seeds. I have learned that the birds prefer to eat. They are thick, and I could make no empty shells in the goods. A 25 kg bag holds 5-6 months if you feed daily (depends of course also on the bird life, which is quite high for us). One should not be stored unlocked (eg in an open bucket) in the apartment, but in the basement because here like moths settle the cores. I would prefer the basement or the garage and store a small amount in a tightly closed container on the patio or balcony - these animal feed blades make here also good restaurants (though you have to buy additionally).