And the recent stuffy,不幸的是，潮湿和阴森的天气把这些小动物带回到了雷达上。
Horseflies,which can also be known as clegs,possess razor sharp jaws and can give a very painful bite,the MEN reports.
Whereas midge bites are little more than an inconvenience,马蝇的叮咬往往需要更长的时间才能恢复，因为它们实际上是切入皮肤，而不仅仅是刺穿皮肤，导致感染的危险。
A number of people have already reported being bitten by the flies over the past couple of weeks.
One person wrote on Twitter: "Saw the first horsefly of the summer and i still hate them."
And another added: "It's finally horsefly season those little vampires love taste of me."
What are horseflies?
They're large,深色果蝇，大小约1厘米-2.5厘米。They're generally found near to cattle,horse stables,ponds,游泳池，woodlands,还有草地，因此得名。
The flies aren't just into horses though,they'll happily snack on any large warm-blooded mammal,including humans.
只有雌性会咬人，因为它们需要血液来产卵。它们锯齿状，saw-like teeth which slice open skin,然后，他们释放一种抗凝剂来阻止血液在他们享用美食的时候凝结。
How do I know if I've been bitten by a horsefly?
If you're a little squeamish you might not want to see what a typical bite looks like,但是如果你好奇或者担心的话，下面的文章里有一张照片。
First off,you'll know about it pretty quickly.The bites are painful and itchy.
Horsefly bites can develop into large,red,itchy,swollen bumps within minutes.对大多数人来说，他们是完全无害的，but they're extremely uncomfortable.
也有人说感觉很热，weak and nauseous.
An infected bite can result in redness,渗出，and extreme pain.如果你感染了，去看你的家庭医生。
In exceptional cases some people can suffer an allergic reaction with symptoms including dizziness,wheezing,difficulty breathing,你的嘴唇或舌头上可能会出现斑点状的皮疹和严重的肿胀。
如果你有任何这样的反应，seek medical help immediately.
What should I do if I am bitten?
It's important to keep the bite clean because if bacteria gets into the skin it can become infected.在极少数情况下会引起蜂窝组织炎，软组织的感染。最好用消毒肥皂和温水清洗伤口。
Apply an ice pack to help soothe the area and stop the itching.
And it goes without saying that you should avoid scratching the bite.It won't stop the itching and could damage the skin,increasing the risk of developing an infection.
Official NHS says: "A bite from a horsefly can be very painful and the bitten area of skin will usually be red and raised.
“马蝇咬伤可能需要一段时间才能愈合，并且可能会被感染。See your GP if you have symptoms of an infection,such as pus or increasing pain,redness and swelling."