Ricky goes hunting for midges
Kids from Audenshaw in Manchester have a problem. Twice a year they're invaded by thousands of midges.
The tiny little flies breed around the reservoir near their homes and, when the babies become flying adults, swarms of them take to the skies.
Newsround's Ricky caught up with the children to find out more.
"Some kids can't play in their garden because of them, while others have to race into their houses and slam the doors to stop them flying in.
Some kids have walked into whole clouds of the things AND swallowed a few! The kids of Audenshaw in Manchester are under attack.
Fortunately, it only happens for about two weeks every year but for those two weeks the unwelcome visitors get everywhere.
Ricky at the lab with Ajay and Maria
This particular sort of midge don't bite, but they really annoy people who live near the reservoir.
Maria told me how they sometimes get squashed on the washing as it's hanging on the line outside so clothes have to be washed again, which she hates as it's bad for the environment.
Ajay told me how when they used to walk the family dog around the reservoir huge waves of midges used to swarm round them - which really got on their nerves.
The people who run the reservoir - which provides water to homes in Manchester - are looking at ways they might be able to solve this pesky problem.
They've got some scientists at the Liverpool School of Tropical Medicine to work out what strength and combinations of chemical will kill the baby midges - which are tiny wiggly things called larvae.
Midges lay their eggs in water and, when they hatch into larvae, they live in the reservoir until they become grown-up midges with wings.
The chemicals can't be too strong as the water goes into people's homes for washing and drinking.
Maria and Ajay went to see the work in action. The scientists showed them loads of different containers where the tiny larvae were squirming around inside.
Ricky at the reservoir
The scientists had taken the larvae directly from the bottom of the reservoir.
When they stopped wiggling and went all stiff, the researchers could see that the chemicals had worked and killed them.
They then tell the owners of the reservoir what levels and mixes of chemicals they need to use if they want to get rid of the midge problem.
When I visited the school the midges had started to die off but the kids in Audenshaw know that until the problem is sorted, they'll be back again at the end of the summer and, when they play out, they'll have to keep their mouths shut!"