It's true, Peter. The mother bulb does tend to rot and sometimes disintegrates.
Those bees do get lazy at this time of year and they're often asleep but at least they don't snore.
Where do you live, Peter, that you don't have frost yet? Our frost arrived 11/12/13.
It took us days to get all the dahlias dug and now they're all out on a table (outside) draining and soon (when it gets a bit warmer) I'll finish packaging them for their long winter sleep.
Two branches had broken off from the main stem of this one and left it filled with water. The water doesn't bother me, that's why I have them draining, but had it been snow or ice it would have meant death for the dahlia.