It wasn't exactly Flying Ant Day in Sheffield yesterday but many residents reported seeing the insects swarming around the city.
Leeds was worst hit by the ant 'invasion' yesterday but that didn't stop some of them migrating south to annoy people in Sheffield.
Some residents reported seeing the flying ants yesterday evening and took to Twitter to issue a warning.
Marie Collier said: "I think the ants are on the move #flyingants #sheffield"
Twitter user MrGee posted: "The Flying Ants Are Out In Sheffield...!! #flyingantday"
Our own multi-media sport journalist Chris Holt posted a video of hundreds of the flying ants outside his home in Crosspool, saying he was "surrounded by the wee beasties".
What is Flying Ant Day?
Flying Ant Day is an informal term for the day on which queen ants emerge from the nest to begin their nuptial flight.
The day happens every year, at slightly different times in different cities. That day has come for Leeds today.
In most species, the male ants fly alongside them, although they are smaller and less noticeable.
The queens fly around – some covering very long distances, others only a few meters – then mate and drop to the ground, where they lose their wings and attempt to start a new ant colony.
This phenomenon occurs in many colonies simultaneously when local weather conditions are appropriate.
It therefore has the appearance of being a 'timed' event or that the ants somehow communicate.
However neither of these is likely to be the case – it is simply a common response to temperature, humidity and wind speed and time of year.