flies are back. I guess they were hibernating somewhere that's warmer now it's cold enough that the thermostats trigger, or maybe they came in with fruit.
the quality is lower than ever. I think I my K/S ratio for this batch is ~9/13, including grabbing one out of the air with one hand, and I can't see why I'd have improved. the traps seem to be doing worse, though.
hypothesis: it's still too cold for them, so their metabolism is slow. that means they're less desperate for food, but also have slower reflexes.