Inadvertent Worm Farmer

(Come to think of it, worm farmer isn't really right. It implies some kind of commercial enterprise. Like the politically correct dog owners these days, I will call myself a worm guardian.)
I never really wanted a worm bin--too much responsibility, like having hundreds of pets. But our compost bin has over the past few months turned into a worm bin, and now I go and check on the little creatures every day. My invitations to my sons ("Wanna come and see some worms?") have so far met with polite declines. But my husband is my partner in worm husbandry. In fact, it is he who is responsible for our compost becoming the home of several hundred (or more?) red worms, since he confessed to occasionally tossing worms in there from the garden. I guess at least two of them* were the right kind, because there has been a population explosion and our bin is writhing with them.
They don't exactly need a lot of "care." They need fresh compost to eat, which we were doing already by feeding the compost bin our vegetable scraps and trimmings from our garden. They need moisture, which we added when the compost seemed a bit dry. We have taken to adding ripped up strips of newspaper since the worms like it--in fact, this morning I caught my husband outside with our office shredder, shredding paper for the worms. And that's about it.
I became curious the other day because I noticed that sometimes they seem to collect on the sides of the bin and even the underside of the lid, so when I pulled it off there was a mass of them. I searched through a few sites about worms, but all I could find was a description of something called "worm crawl" when all the worms decide to leave their bin together in a mass exodus. This was not happening--thank god! Sounds scary. The only thing to do was to email my farmer friend Karen, who lives on a real farm and who several years ago originally urged me to get a worm bin and showed me hers. At that time I was not hip to worms and politely declined.
Karen responded that her worms sometimes climb up to the top of the pile or the sides if it's too warm for them, or too moist. I was reassured to read this: "My worms regularly come up in a huge, roiling mass --and they often climb on the lid to my container." So, nothing to worry about.
The hardest part is separating the worms from the compost when I'm ready to use it. Specially-designed worm bins have separate sections for adding new compost so you can let all the worms migrate to the new compost before harvesting the castings. But everything gets pretty much mixed up in our bin. When we harvest our compost, we have to sift and separate out all the undecomposed stuff anyway, so I have been trying to pick out the worms and put them back in the bin. But quite a few go along with the compost back into the garden. Sounds like I'm doing pretty much what Karen does: "To remove more worms from the castings, I have tried piling up the castings in the sun to encourage the worms to move to the bottom, away from the light. It was more effort than necessary, so now I don't worry if some worms get placed into the garden."
My nieces are coming over for dinner tonight. I think I'll take them out back and show 'em my worms.

*Yes, there must be two of them, because even though worms are hermaphroditic, there must be two of them so they can rub their clitellums against segments 9-11 of their mating partner, depositing sperm in each other's bodies. For a more in-depth discussion, see the excellent description on the Backyard Nature site.