I have these too! I posted once before and didn't really get an answer. They have multiplied and also are on the pieces of cardboard. I would love to get rid of whatever it is. They really don't seem to move, but when you put the food in they appear. I've tried baiting them out but they just don't go away like the mites did. I used to get food from a grocer, and I wonder if they came from boxes from another country? This was also before I froze all my food. Sure hope we get some help on this.

Sounds like mites to me. These do no harm to the worms and actually are a benefit to your system, they eat the food items you put in your bin and not the micro-organisms that the worms are after. They benefit the system in that they get to work on the food that is just beginning to decompose and their waste becomes worm food as well. They are not worm predators so there is no worry there.

They can be a nuisance if their population explodes to the point at which you start finding them outside the bin, especially if the bin is indoors. They tend to thrive in very moist conditions so if you want to reduce their numbers a good layer of dry shredded paper, cardboard, etc. on top can help. When adding very moist foods, like watermelon for example, try putting it under dry bedding or adding dry bedding on top of it. Another thing you can do to minimize mites is to bury the food but you should educate yourself about compost heating up. If you do it in the right proportions you can make it hot enough to kill worms. This forum and http://vermicomposters.ning.com/ have lots of info on this.

No one adds mite eggs to their worm bins but they appear tend to appear out of nowhere. I'd say it's impossible to get rid of mites completely, they are everywhere. One thing you can do to minimize populations is to put a really wet fruit on the surface (melon) and let the mites colonize on it. You can then remove the fruit with the mites, hopefully in a cold compost pile and not in the garbage. If you don't have a compost pile how about in a far corner of your yard to let it dry out? That should kill the mites after it dries and the fruit can be put back in the worm bin.

Kind of a long post but it sounded like you didn't get an answer before and I know there are a lot of people out there with different opinions on mites.

Thank you for the info on mites. I do have red mites, and now I have some more ideas on how to control them. I don't think these white things are mites though, unless the white mite is smaller and doesn't appear to move at all. It really does look like salt in the bin. This white thing also gives the bedding and vc a shredded appearance. If this still sounds like white mites, I'll start treating the bin for that.

Thanks much, Rom!

Yes, I believe you're correct: the little critters are mites. It's good to know they are not the larval stage of something unpleasant.

Last evening I moved the bin containing the trays to a spot where I could remove the lid and poke around a bit. There was significant condensation on the inside of the lid -- enough so that it was dripping when I lifted it off of the converted under-the-bed storage bin.

I noticed that the mites were concentrated over the areas where I've been burying the food items. Hardly any on the shredded cardboard on the other side of the worm trays. I also observed that they were primarily on the top surface, with very few in evidence in amongst the worms.

The bedding seemed a little too moist, so I did add a fresh layer of cross-cut cardboard. Hopefully this will bring down the humidity to some degree, reduce the mite population a bit, and give the worms a little more space to do their thing.

I was very pleased to see small worms among the original population I bought from the local pet supply store. The bin is probably too large for such a small population (~150 in the initial batch), but I have evidence that they ARE reproducing. And I saw a small accretion of wet castings along the sides of the lower worm tray.

Small population won't last long if you keep the conditions as ideal as possible. They reproduce fast when it's warm, moist and there's plenty to eat.