Losing battle

For several weeks now the hen pheasants have been picking and scratching their way across the "lawn".  I assumed they were looking for bugs to eat.  Increasingly frequently, one would stop and scrape out quite a large hole and then sit, fluffed up, in it.  I would race out of the house waving my arms and shouting, to their mild astonishment.  Eventually I started filling up the holes and putting something on top, like a old roof tile, to stop them.  But they just move on to another patch in the lawn.  Eventually I gave up and collected my roof tiles.  I was surprised to find that the underside of each was crawling with ants.  The pheasants appear to have been digging the top off ants nests and then sitting on them.  I can only imagine that either they like being tickled or the ants remove parasites.  So here you have four pheasants possibly having a communal ant bath.