Just an observation: With the 80 degree weather that started here in southwest Florida this year, I started seeing egglaying from wild BSF in late January - fully a month before last year.
I had discontinued all but one bin, (my BioPod which I had moved into my greenhouse tent back in December). Last week, i decided to restart one of my outdoor bins. I had a plastic sack of sweet feed I had left outside. Though waterproof, evidently there are microscopic openings along the stitched top of the feed bag. The feed was dry (though naturally a bit moist as it was when packaged), but when I opened the bag, there were thousands of BSF larvae crawling around in it. I can only assume eggs were laid nearby and the microscopic larvae found their way into the sealed bag through the stitches. These are amazing little critters with one heck of a will to survive!