Well if you were in the UK I would say certainly Ants.
At certain times you get Flying Ants, 2 sizes, the larger are females who
will fly off then when they land they will shed their wings and look for a
place to start their own colony, the smaller are males who also fly with
the females, mate in the air then that's the end of them.
When they are ready to fly, often in thundery heat in summer, you will see
masses of birds such as sea gulls feeding on the wing as the ants rise on
thermals, up to several thousand feet.
you can have clouds of them consisting of many thousands of ants.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk