Well, honestly. The easiest way, that Ive found, personally, is to buy a very large strainer.. one that fits on top of a 5 gal bucket, and slowly pour the bins into the sifter and sift as needed. This helps get rid of alot of the fully processed substrate, while also seperating the larger worms/beetles. Once you get one bin sifted one time through, put the ones in the sifter somewhere, then do that bin again.. You will find tons of small ones that you didnt see before. Hopefully that will help. Thats what I do w/ all of my mealworm colonies!