I have been keeping my eye on a number of ants' nests in our wild garden for some days. There appeared to be little activity until yesterday afternoon. We were having a cup of tea and a slice of chocolate cake when we noticed plumes of insects rising into the air. A few minutes later our regular garden birds, especially the Blue tits and Blackbirds, started swooping and fluttering for the airborne ants. It was quite a spectacle to watch.
David made a short video recording which you can view here: