Weird phone calls

[Hurrylater]

Recently (last 3 months) I've had a spate of calls from various numbers that hang up after I answer.

If I call the number back the call doesn't connect.

What's going on?

Sales/scam calls. Call centres dial several numbers and connect to first to pick up, dropping other calls.

Scams? Lots of them put the phone down as you answer. If you have their number you can Google it. There's a site such as Who Called Me. There are others as well.

That makes sense, I'm just blocking the numbers now, but I assume they have an unlimited amount, so blocking is probably futile.

The numbers are always mobile numbers rather than landlines.