Bugzz!
Greenfly are no strangers - the cherry tree overhanging the garden is rife with them, but this was different.
Black flies infesting the poppy seed-heads and being tended by an army of very small ants that live in the wall.
Took photo's in situ but the camera couldn't focus on them, too many distractions for it, and I couldn't see the miserable failures on the screen, too bright.
Had to set it up on a tripod and cut one off that it could focus on - of course the ants didn't hang around for a photo-shoot and buggered off smartly - most of them anyway.
Surprises me how many miniscule spiders and beetles live in the seed heads (I collect all the seeds from the flowers and 'recycle' them).