I saw a few worms made a break for it and died on the floor near the bin. So delved in (gloved hands make this easier) to see how they're doing. Turned up and loosened some compacted bedding from the bottom, but for the most part it was in good condition, damp enough, no awful smells. The worms are slow, but have good color and their skins nicely moist. I think they were just too cold. I put another layer of cardboard between them and the outside house wall. And picked out this small handful for the fishes.
To clean them for fish food, I do several rinses in tank water. The first to remove compost bits. Then let them sit in a shallow container - one that has a raised center, they can crawl out onto the island if really make an effort- and check it once or twice a day. If they've extruded some waste, I dump the water out and replace, until it stays mostly clean.
Perry ate his bites, not terribly enthusiastic, but she did. Most of it I dumped into the main tank. Serpae tetras went nuts. Trying to steal pieces from each other, darting away to hide in dense plant thickets with their spoils. Shrimps sneaking in for their share. But really the kuhlis got most of it. Funny thing, the tetras couldn't seem to see the snail portions that lay on the substrate. They'd be looking right at it, but not see it until a kuhli found via scent and started eating. Then the fish quick would steal it and dash off, chased by others. Kuhlis still got plenty, though. I haven't done this in a long time because it's rather messy to prepare the snails, so it sure was a treat for them. And of course I'd rather give my extra snails to someone than boil them, will do that in spring if I need to cull again.