It’s only the women.
Male horse-flies buzz sedately from flower to flower, feeding on nectar. But, female horse-flies need protein (it’s an egg thing).
And how they get their grizzly diet is reasonably brutal, according to Dr Whitmore, Senior Curator of Diptera and Siphonaptera at the Natural History Museum. (Which is possibly the most splendid job title in the entire world – Frank).
First, they saw deep into the skin with a pair of serrated mandibles strong enough to hack through cow hide. Then they rub in saliva to keep the blood flowing while they slake their thirst
Horse-flies have hit the headlines during the hot weather but it is thought more people are getting bitten (sawed?) simply because more people are outside
The good news is that horseflies are a particularly good meal for bats – so you can feel you are doing your bit for nature as you nurse your painful red welts.