Has called but does not leave a message.

I also received a call from this number. I did not answer as I was at work.  No message was left.

This number calls my residence twice a day for the past three months.

This is an automated call from the Lee County Library System.  My kids use it all the time.  Your number is attached to a reservation for a book, video, etc.... and the calls are to inform you that it is in and waiting for you to pick it up.