Swallow and Martin behaviour - part two

Well, they are still at it.  It seems to be mainly Martins.  G tells me the joints (the black bits) on the aerial are slightly sticky and on inspection with the trusty bins it does look as though they are trying to peck at the joints so perhaps they are after small insects which have become stuck to the aerial.  However G has said he has seen some landages.  I also get the feeling they are more likely to indulge in this activity (although I haven't really monitored it) when it is windy so perhaps the insects are either an easy static snack in windy weather or perhaps they are blown against the stickiness and can't escape making a convenient titbit to snatch in passing....
On a  probably slightly sadder note, the swallows who are now nesting at the corner of the house, having spent the entire summer faffing around in various other places, decided a couple of weeks ago to raise a family - I don't think the new 'uns will make it away to join the others in the photo as they haven't left the nest yet but we can still hope...certainly one of the parents is doing a really good job of scaring away any humans ( me!) who should have the temerity to put anything in the bins beneath the nest - Rubbish bin tactics now consist of tiptoeing round to the corner of the outhouse, seeing if anyone is in and if not shooting to the bins, jettisoning rubbish and scuttling back to safety tout suite!