These guys do not know how a doorbell works.
My doorbell is loud enough to wake up the entire block, yet Mr. UPS guy keeps saying I must have been away or simply did not hear it. He also says that it might be broken, but really, it is not. He just does not know how to press a small button, that has the same name on it as the package he is supposedly delivering, in order to do his job.
I have received two notifications from UPS so far, both stating a date and time that I was at home and would have heard the doorbell had it been used.