The hot weather dries out footpaths but brings out horse-flies. These are large hairy flies of the insect family Tabinidae. Their bites are painful, take longer to heal than other insect bites and can become infected.
Only the females bite. They have long mandibles which cut the skin to gain access to blood unlike, for example, mosquitoes whose bite pierces it like a needle. Horse-flies can bite through clothes. They are found in damp areas, in woodland and in areas with livestock; and are active in the day and less so in windy weather.
There is little that can be done, once bitten, to stop the reaction: pain, swelling, redness and itching. Scratching can delay healing. Application of an insect-repellent containing diethyl-meta-toluamide (DEET) can help reduce the risk of being bitten.
I was the last creature to be attacked by the horse-fly that bit me three days ago. It bit the back of my right hand and stayed there too long. I squashed it. The bite is less itchy but I still have a red lump the size of a five pence coin.