Webby bits...go through, handful by handful and delicately remove every bit of those to the chickens. Screen the tops of your other bins--if you're right and it's moths, you'll thank me later.
You might consider just feeding out that one bin if the above doesn't work; scrub and start that bin over.
ZanyChick, welcome to insanity

. It really is well worth the time to go through all OMG HOW MANY pages of this thread (yes, really all of them) and read it end to end. It took me two days.....on dialup.
SteveBaz, yes, I've started over and over

.
I don't worry about sterilizing the bran. I know, I'm weird but so far so good. The chickens, I figure, will eat anything that moves, so things like grain beetles don't bother me. The moths around here are far more interested in critter fiber, so no worries there...and not humid enough for mites (which is nice).
When you're down to just beetles, don't give up! There's more going on in there than you know. Change your beetles over to a fresh container and fresh bran, and hold the first container for about a month, checking weekly by scooping a huge handful and then sitting very still and watching the bran. You're looking for tiny flake movements--lots of them. You won't necessarily see the larva yet, but a big magnifier helps.
My delay from beetles-only to Hey Wow Looka This was about a month, and another two weeks down the road, I'm sifting out feedable worms again. Not a lot, but some, and there's still zillions of teensy tiny ones in there!
You can buy and start a whole new batch in addition, to spread the ages out a bit, but natural variation in egglaying will do that for you if you are patient.
I've never yet seen a patient grasshopper, so I'll just say PERSISTENCE, instead.
