I keep them in the sacs, easier to find them that way. Basically they spin this web-like stuff around them (kinds like a silk worm) and it gets all stuck to the bedding stuff and gets a mess so keep them in the sac, make a little hole to get out the ones you need and I find they stay in there and don't come out. Make sure you take what your Cham doesn't eat out of the cage cos those suckers climb our of my feeding cups! My Chams love them though and they last in the fridge for a LONG long time. I remember the first time I ordered some, opened it and saw the sack all rolling and moving..looked like an alien was about to pop out!