Why are midge bites so itchy?

While there are few that would grudge the return of warmer weather after a seemingly endless winter, many a hiker, dog walker or picnicker has cursed forgetting the insect repellant as swarms of tiny bloodsuckers attack.

Yet some people seem relatively unaffected by the winged beasties.

So why are some people attacked more than others, and why are midge bites so itchy?

There are five species of biting midge in the UK, Culicoides Impunctatus - the Highland Midge - and Culicoides Halophilus being the most notorious. It’s the pregnant female that attacks humans in order to source protein to develop her eggs.

The midge will pierce the skin with her mouth and pump saliva into the wound to prevent it clotting. It’s this saliva which causes a mild immune response in humans, resulting in itchy red spots as the body seeks to repair the wound.

For some, the irritation lasts only a few minutes, but for others the itching can last an infuriatingly long time.

The NHS warns that some can experience bullae - fluid-filled blisters - or weals - circular, fluid-filled areas around the bite - as a result of allergic response to a midge bite.

And, according to some experts, it’s your smell that makes you a midge magnet.

Jonathan Day, a professor of medical entomology at the University of Florida, suggests that biting insects such as mosquitos - and close relations midges - are chiefly attracted by the amount of carbon dioxide you exhale. As well as carbon dioxide, lactic acid and estradiol found in your sweat can act as an attractor.

Your body heat is also thought to be an influence on how attractive you are to midges and pregnant women are thought to be more attractive as a consequence.

So how can you avoid being bitten?