Dave Nelson

luckily, just before winter i took out a handful of worms and put them in a (very) small indoor bin as a seed population in case the outdoor bin doesn't recover.

I would miss mine if I had to wait until spring to check up on them.

I liked the novel idea of using an aquarium aerator pump to push warmish air from inside the house (at room temperature) directly through a half inch pipe to the outside worm farm. It would use a trivial amount of electricity (after all these little air pumps are designed to be left running continuously for months).

If you wanted even warmer air in extreme conditions - put the air pump into a cardboard box with a low wattage light bulb. Obviously you should always bury or insulate the feeder pipe and put at least some insulation around your worm farm.