You got a big chest freezer? If your feed is coming already contaminated with the immature weevils then a stint in the freezer would kill them off. Some farms have an extra freezer in the barn or garage and if it's empty then put it into use.

I've always called them granary weevils..This is an indication that the feed may be old. Almost all feed, cornmeal, flour etc. will have these in it when it gets old. I always freeze all this kind of stuff for a few days when I first get it.(I don't freeze chicken feed) This kills the eggs that are invisible, and any weevils already hatched. Unless the feed is kept inside your dwelling, don't worry about them. They won't eat enough feed to hurt. Just feed them, along with the feed, to the chickens. I'd suggest buying your feed at a place that sells a lot of feed. You'll more likely get fresher feed, at least feed that has not had time for the weevils to hatch. Watch Out ...Some types of these little devils will bite you just like chiggers....TERRIBLE itch and sores.(you may have another kind)I had over 100 bites once just by moving an old bale of wheat straw. They apparently had infested the seed heads inside the bale.....Misery.

Also, make sure that you have thoroughly cleaned your feed storage areas....