I think it does yes, then you hear a milkman clinking bottles I think, as if its early morning. I never miss it...particularly as Black Rat is now almost certainly extinct as a wild mammal in UK. ( Bristol's are probably from a lab or semi-domesticated strain)
Interesting, its never occurred to me - probably due to not giving it any thought - that there may be such a strain of black rats. Dudley's too possibly?