[driftdiver]

You can also mix DE powder (food grade Diatomaceous Earth) in with the grains. Its cheap and you put about a tablespoon in each bucket. It will kill any bugs that get into or hatch in the grain. It works quite well.

You can also freeze the grain before storing. The freezing will kill the bug eggs.

[SisterK]

How interesting. Diatomacious earth is one of my favorite pesticides, but I also know folks who put it in their animal feed specifically to keep internal parasites down.
Never occurred to me to put it in my feed.
Alas, My freezer is too small to even temporarily store stuff.