Calls all hours of day and night. Sometimes hangs up the minute you answer, sometimes just listens - or is a robo caller, then hangs up. Never leaves messages, and when you answer they never speak. Calling back the number leads to a 'google caller' voice message with a generic female robot voice telling you to leave a message.    If this is a telemarketer I don't understand the point unless it is to harass, or possibly a thief trying to determine people's at-home patterns.