A swarm of flying ants so big it shows up on weather maps is heading towards Essex. 

The Met Office's weather may appears to show a large blue area covering the south East. 

At first glance you may think it represents a large rain cloud, but in fact it shows the huge swarm of flying ants.

There are so many flying ants they are appear on the Met Office's weather radar, with the gigantic swarm "at least 50 miles wide". 

The invasion comes as a mini-heatwave is expected to hit Essex this weekend.

The Met Office tweeted: 'It's not raining in London, Kent or Sussex, but our radar says otherwise...

'The radar is actually picking up a swarm of #flyingants across the southeast. During the summer ants can take to the skies in a mass emergence usually on warm, humid and windless days #flyingantday'.