Caller ID says "PROLIFE NEW".  They leave no message.

I do not call them back.

I checked out another site which claimed as "Alias" did above that it's a scam about a vacation package.  The caller ID doesn't match that.

"Prolife New" is generic enough to match tons of stuff.  I suspect this generic ID is used to complicate an investigation of them.  This is not a good sign.

I searched 800 notes.  There are a large number of numbers associated with this ID.  This is another bad sign.

I read the threads for a few of these numbers.  Generally, they ask for a specific person.  They then say they are doing a survey (makes no sense; the statistics are stable and well known) and ask if you are pro-life or not.  They don't seem to be asking for money.

I suspect a scam:
1) They could be looking to see who answers.
2) Could be rying to confirm their data about who lives where.
3) Or hoping you'll say "yes" to something.  They could then splice your "yes" with some question like "Do you want to transfer all your money to Prolife New?"

Anyway you look at it, I would discourage responding to them in any manner.  Block them!