M.M.
I have plastic cereal dispensers form Walmart or Target. A couple are Rubbermaid and I know I have a few Sterilite. THey kept al lthe creepy crawlies out of my cereals in NC. So far I have seen none here in VA.
I rip of the top of the box and throw it in on the side then take the bag and either rubberband it or I have wooden clothes dryer clips or use Gallon size Ziplocs. I have also put my sugar in a Ziploc in my sugar canister on the counter.
We go through one BIG box of Honey Nut Cheerios every week it seems.