Someone keeps calling them when I answer they hang up?

This is gonna sound strange but I’m serious about this actually happening. Throughout this week there’s been around 4 calls thus far from an unknown number. I’m in Galway Ireland and the number is calling from Dublin Ireland. (200km away). I don’t know anyone in Dublin and I’m very careful about giving out my number. It calls randomly and the second I pick up like “hello?” It hangs up. Nobody is on the other end. My friend was telling me it’s a possible scam where they want me to call back so I’m not gonna call back. What could this be and how can I stop this.
Answers

John

In America it has become so bad that legislation is constantly being devised but it only works for so long. Just a constant barrage of junk calls and truly most of them are white collar crime.

Bookbinder

I live in England, and what you describe happens often over here. Your friend is probably right, it is likely to be a scam, so do not call back. Some telephone marketing firms work like this: they have a big call centre, with lots of computers. The operators set their computers to generate random phone numbers, and, when the computer finds a 'real' phone number, it automatically dials that number. That could be what's happening to you. If you pick up the phone and you don't hear anything immediately, that could be happening because the computer operator is already talking to someone else, whose number has been found by his computer. Always hang up if you get a call such as you've described. After all, a phone call is usually more important to the person who's calling than it is to the person who's being called. If it's important, they'll call back, and they'll make sure that they get to speak to you.

SumDude

In America we have learned that one cannot stop junk calls. If you have a number, you can try asking a "reverse directory" who it is. {You may be charged a small amount.}

Ibis405

The culprit is Sarcastatron, he's not very bright.

Maxi

Block the number or report it

mitache

Maybe it's your crush

Orla C

Block the number on your phone.

Karen L

I get calls like that pretty often on my landline. As others have said, telemarketing companies (and scammers, if I may differentiate between them which is not always easy to do) use automatic dialing systems and just call whatever number is next on the list. I believe they use the fact that you answer or not to establish a time when you are likely to answer the calls, so eventually a human can call you and try to sell you something. Or scam you, as the case may be. Over the years I have found that after getting half a dozen of these calls with no one on the other end, over a couple of weeks or more, I can confidently expect to get a call from an actual person from the phone company, the satellite TV company, or someone who wants to fix my computer. If no one is there when you answer your phone in the first second or two, hang up. Sometimes, no one answers right away because their phone system takes a few seconds more to establish that the call has connected and to get a human on the line to speak to you. If that is the case, you don't want to speak to that person anyway.