Flying ants

The swarms of flying ants that interrupt Wimbledon every year are usually Lasius niger, the black garden ant.

A black garden ants’ nest is, for the majority of its time, entirely female. But when the nest has reached the right size and level of preparedness, the queen begins to lay eggs that will develop into males and virgin queens, both winged. But this new sexually mature generation all share the same mother, they are too closely related to breed. They have to leave their home nest to find and mate with counterparts from other nests.

So, on a warm, humid and still day, the new queens and the males from all the nests in an area will take to the air in swarms that can be so large they show up on radar and have even been spotted by NASA’s weather satellites. As the winged ants emerge from the ground, they scatter in all directions to maximise the chance of mating between different colonies and thereby reduce the chance of inbreeding.

During her flight, a successful queen will have mated with many males and stored enough of their sperm to fertilise all the eggs she will lay in the rest of her life, which could last as long as fifteen years. The males, on the other hand, die very shortly after mating: their only purpose was to carry the colony’s DNA away and mix it with that of a queen from an unelated colony

When she has mated, the queen looks for a suitable place to establish a nest. It’s hard to tell what she is looking for, but when she has found it, she chews off her wings and disappears underground. She excavates a chamber in which she lays the new nest’s first few eggs and rears her first brood of daughters into adult workers.