A BIBLICAL swarm of flying ants may descend on Winchester today due to the warm weather.

The winged creatures are already flying around the city centre in their thousands, but if forecasts are correct, today, July 18, could see an event worthy of the Old Testament.

"Flying ant day" is an annual event when the insects come out of their nests and swarm together as part of their mating ritual. It tends to occur in hot and humid weather, so today's conditions are ideal.

READ MORE: 3 ways to keep flying ants out of your house this summer

A rather lonely-looking flying ant in Winchester city centre (Image: Kimberley Barber)

Ants tend to fly earlier in urban areas than rural areas, probably because temperatures are generally warmer in urban environments.

Experts say there can be several flying ant days each summer from mid-July until the end of August, weather conditions permitting.

Flying ant day happens at different times in different parts of the country: social media users across the South have been posting photos and videos of the airborne critters for several days.