Bugs in the chicken feed. Homesteaders and even non homesteaders will at some point in their lives run into weevils. They will arrive as eggs or even live bugs in flour, corn meal and other grain products that you buy for your kitchen.
Freezing these things for a week or so will prevent the eggs from hatching, kill any live bugs and so prevent the weevils from spreading to other grain items in your kitchen. We the same thing applies to chicken feed. Murano Chicken Farm shows you what they look like and how to deal with them if you do find them. They also suggest ways to prevent them. I know I got weevils in flour one time and while I know it can happen and I know it is just weevils, when you find your food stuffs just crawling with bugs it really creeps you out and you want to throw away every speck of food in the house and start over with putting all new food into glass jars right in the trunk of the car so it is all sealed up tight before entering the house where you were attacked ( okay, grossed out ) by weevils. But with precaution you can prevent it from happening.
I did get them once but I learned to freeze grains products as soon as I bring them home so I have never had them again. While I am sure trying to freeze 50 pound bags of feed is probably not feasible for most folks this article does offer easier solutions for bug in the chicken feed or more like how to prevent them.