In some parts of the UK, swarms of flying ants have been already seen - near houses, on streets and on cars. The phenomenon is related to the fact that during the mating period female individuals "put on their wings", and after mating they fly away from their colony and built another colony, which can grow up to 5,000 ants. In a kind of cell, the mate brings the first offspring, but then chews off the wings as unnecessary.
Flying ants is a very short-term, literally not more than a couple of weeks, a seasonal phenomenon that occurs in July-August. The day, when most of the ants begin their journey is called Flying Ant Day, although, of course, not all ants will fly on the same day. The locals of North London were among the first to meet with the ants.