Just had the same problem with my mealworms. Looks like a Grain mite population explosion. It's really gross because they're just everywhere.
Here's the thread, that link provided by Josh is a pretty good read particularly the section on grain mites.
http://www.ball-pythons.net/forums/s...ad.php?t=99796
About all you can do I guess is put the bag in a sub zero freezer for a few weeks or so, though I wonder if heating it up in an oven would work the same way? Maybe 160 degrees for half an hour or so? Probably just best to throw it out and buy some new stuff.