Black ants preparing for nuptial flight

The black ants are getting busy in our garden preparing for their nuptial flight. In the back garden on the rockery they have been building a huge mound of soil - an amazing feat of earth moving for their size.

From past experience I have found the nursery chambers are beneath the rocks that absorb and retain the suns heat. The ants are now building soil chimneys up the side of one of the rocks.

Back on 23rd July, a aborted nuptial flight took place at 5.50pm from the nest outside of our garden beneath the pavement.  

A few of the queens left the nest and some were eaten by sparrows that found them on the ground. But they seemed to change their mind (wrong environmental conditions!) and went back inside.