As horseflies sweep the UK, Liz Connor explains all you need to know about dealing with these blood-sucking insects.

Summer is a brilliant time for getting outdoors and enjoying the best of the UK's beaches, forests and grassy spots.

But it's not just humans that are basking in the good weather, as the sun often brings out unwanted pests.

Horseflies thrive in hot weather, and their bites can be painful, due to their razor-sharp claws. Also known as clegs, these dark-coloured creatures are about 2cm in size and tend to be found near horse stables, as well as ponds, woodlands and grassy areas.

To help runners, cyclists and families who are planning to enjoy the great outdoors, we've rounded up all the information you need to know about horseflies and avoiding getting bitten this summer.

Why do horseflies bite?

Much like mosquitoes, female horse flies feed off blood, so they can produce eggs. Their saw-like teeth slice open skin, while releasing an anti-coagulant to stop the blood from clotting as they eat. The bites can take longer to heal than a mosquito, as they cut into the skin, rather than just piercing it.

As the name suggests, these large flies like to feed off horses, so you'll often find them buzzing around stables and fields. However, they'll feed off any large mammal they can access, like cows, dogs and humans.

How to know if you've been bitten

Horsefly bites are painful and itchy. If you're unlucky enough to get one, you'll notice red and swollen bumps resembling blisters and burn marks appear on the body within minutes of the horsefly coming into contact with human skin.

According to NHS Choices, most people will not feel any other symptoms, but some may also experience a larger red, raised rash (called hives or urticaria), dizziness, weakness and wheezing.

How to treat a bite

First things first, avoid infection by keeping the wound clean with antiseptic soap and warm water. Although it's difficult, you should avoid scratching the bite too, as it won't stop the itching, and can increase the likelihood of an infection. If you're struggling, ask your pharmacist for a steroid cream containing hydrocortisone or ibuprofen, to help ease pain and swelling.

If your bite becomes infected or starts oozing, you should visit your GP. In rare cases, some people suffer allergic reactions, so seek immediate medical attention if you feel dizzy, notice a skin rash or severe swelling in your lips or tongue.

How to avoid a horsefly bite

Unfortunately for sun seekers, these flies are not especially inhibited by insect repellent, so the best way to stop your summer being ruined by a painful bite, is to cover up with long layers and keep your windows closed during the day.