is it a case of, 'if it happens, it happens'
That's about the strength of it ...
I often liken the catching of swarms to fishing in the open sea - you can only catch something if you chance upon a shoal of fish which just happens to be passing nearby.
Of course the odds become significantly increased the more beekeepers (specifically, the more inexperienced beekeepers) there are in your area. So - towns are far more promising for swarm-catching than the open countryside.
Bit like sea-fishing when you know where the wrecks are located.
Well done - now the fun begins ...
Bit of (unrequested) advice - I know it's tempting to 'have a peek inside' - but leave 'em well alone for a good week or even two, until they've got some brood established. Then they'll be anchored ok, and won't be scared-off by any interference.
'best,
LJ