Few years back I bought a couple bags of sunflower bird feed when it was on sale early. That's what I plant, nothing special.
Put the 2 50lbers in the garage.
No mouse issues.
But the mouths started to hatch and they got everywhere in the house.
Fortunately most of my dry goods get put in glass jars with the lockdown lids.
My oatmeal, flour etc survived.
However the moths were in every part of the house and it took several months to get rid of them.
When I sifted through the seed it was hard to find any good ones.
Now I buy the seed just before using it, forget any early sales.