Vampire like horseflies are breeding like never before as Britain enjoys the longest heatwave in 40 years.
They are breeding like never before with the aide of garden pools and the heatwave.
The NHS is now advising members of the public to drain standing water to stop insects multiplying.
These insects love water and the heat will only help them increase in numbers.
The problem comes when they bite you, more that 9000 people have called the NHS helpline 111 to report these insects bites.
They leave a painful bite which often requires antibiotics if they become infected.
According to Dr Nick Scriven, president of the Society for Acute Medicine, bites from vampire horseflies can be especially sore.
He told the BBC: “They actually give one of the nastier bites, because they take a chunk out of you.”
“They can be very painful, and can take a while to heal, and as result can get infected and need antibiotics.”
Paddling pools are prime breeding grounds for these bugs.