A couple years ago I tried freeze dried blood worms. That lasted about a week and a half before I realized how much that was not going to happen with my group of fish. I think they're are probably great for fish that readily eat from the surface, but I dont have but a couple of those. I started feeding the frozen ones, and the fish love them. Nothing was ever left behind. I buy the flat packs by hikari (yes, I'm a huge hikari fan) as it seems to me that there are more worms per square inch and better quality worms over all than the other types of flat packs I've tried. The squares were a nice convenience when I only had a handful of fish. I switched to flat packs and found they store better in your freezer than the cubes and you get so much more for your money.