Received calls from this number

No one at the other end.  Dead air.  why?

I got call from this number, and no one was there, no word, I don't know why calling me ? And some one or company there is person didn't do anything important things instead doing this time loosing.

2014-12-11, approximately 7:20 PM my wife and I were out for a short errand. Our pre-teen daughter received a call at home; caller self-identified as "Sean" and asked for Mom or Dad (not by name). Forgetting her training, she told the caller we were out. He then asked how old she was.

After she hung up she called us and we came home straight away. I tried calling the number back and it rang at least ten times before a beep sounded. I hung up without leaving a message.

We tried to call the number again this morning - same result.

lots of calls, everyday