Appelhof suggests sucking them up with a vacuum cleaner hose if their numbers become annoying. Fruit flies are a good reason for those of Teutonic tidiness to vermicompost in the basement or outside the house if possible.
Maintenance
After a new bin has been running for a few weeks, you'll see the bedding becoming darker and will spot individual worm casts. Even though food is steadily added, the bedding will gradually vanish. Extensive decomposition of the bedding by other small soil animals and microorganisms begins to be significant.
As worm casts become a larger proportion of the bin, conditions deteriorate for the worms. Eventually the worms suffer and their number and activity begins to drop off. Differences in bedding, temperature, moisture, and the composition of your kitchen's garbage will control how long it takes but eventually you must separate the worms from their castings and put them into fresh bedding. If you're using vermicomposting year-round, it probably will be necessary to regenerate the box about once every four months.
There are a number of methods for separating redworms from their castings.
Hand sorting works well after a worm box has first been allowed to run down a bit. The worms are not fed until almost all their food has been consumed and they are living in nearly pure castings. Then lay out a thick sheet of plastic at least four feet square on the ground, floor, or on a table and dump the contents of the worm box on it.
Make six to nine cone-shaped piles. You'll see worms all over. If you're working inside, make sure there is bright light in the room. The worms will move into the center of each pile. Wait five minutes or so and then delicately scrape off the surface of each conical heap, one after another. By the time you finish with the last pile the worms will have retreated further and you can begin with the first heap again.
You repeat this procedure, gradually scraping away casts until there is not much left of the conical heaps. In a surprisingly short time, the worms will all be squirming in the center of a small pile of castings. There is no need to completely separate the worms from all the castings. You can now gather up the worms and place them in fresh bedding to start anew without further inconvenience for another four months. Use the vermicompost on house plants, in the garden, or save it for later.
Hand sorting is particularly useful if you want to give a few pounds of redworms to a friend.
Dividing the box is another, simpler method. You simply remove about two-thirds of the box's contents and spread it on the garden. Then refill the box with fresh bedding and distribute the remaining worms, castings, and food still in the box. Plenty of worms and egg cocoons will remain to populate the box. The worms that you dumped on the garden will probably not survive there.
A better method of dividing a box prevents wasting so many worms. All of the box's contents are pushed to one side, leaving one-third to one-half of the box empty. New bedding and fresh food are put on the "new" side. No food is given to the "old" side for a month or so. By that time virtually all the worms will have migrated to the "new" side. Then the "old" side may be emptied and refilled with fresh bedding.
