Insects are a real torment at this time of year for those, like farmers, who have to work outside.

The main reason there are so many flies, midges and bugs this year is the mild winter. It has allowed more than our normal share to survive.

There is nothing more irritating than flies swarming around your head and face. Then there are light-footed clegs that land unnoticed on bared arms and shoulders before announcing their presence with a vicious bite, or clouds of midges in the evening that drive all but the hardiest indoors.

It's the same for sheep and cattle. Sheep probably suffer the most, as they lie low in the shade of a dyke or hedge during the heat of the day, flicking flies away from their heads and faces with their ears. In the evening, when the midges come out, hill sheep head for high ground where there's often a cool breeze and fewer midges.

Horned sheep, like Blackfaces, suffer from head flies that congregate in clusters at the base of their horns creating nasty sores.

Worst of all are green bottles, or blowflies, that lay their eggs on soiled parts of a sheep's fleece, particularly in humid weather. Those tiny eggs soon hatch out into hundreds of maggots that can quite literally eat a sheep alive.

Sadly, some hill sheep that are struck by maggots die a lingering, painful death out of sight in bracken. A sheep's daft logic often inspires it to hide from pain! The first the shepherd or farmer knows that something was wrong is when the bracken dies back in the autumn to reveal a skeleton.

To help protect their flocks from the likes of flies, lice, mites or ticks, many sheep farmers are busy dipping their sheep just now. That's where you plunge them in a solution of insecticide. Others prefer to pour, small measured quantities of preparations containing insecticides onto the backs of their sheep.

As with sheep dip, the insecticides in those "pour-ons" become incorporated in the lanolin in the wool and on the sheep's skin to offer prolonged protection against a range of flies and bugs.

Meanwhile, cattle bunch together in the shade, working on the fair principle of sharing the flies between them. If they keep their heads down, the flies find it difficult to get at their backs through a bunch of tails swishing in unison.

Nowadays, farmers have a herbal remedy to keep flies away from their cattle. Garlic may not be the best thing to improve your sex life, but old wives' tales that it's good for health have been proved correct.

The strong, pungent smell of garlic is caused by the thiol group of sulphur-based compounds. Flies have evolved to keep away from garlic and other similar smelling plants because thiols interfere with their reproductive efficiency.

The behaviour of flies is innate - they don't think like us as their behaviour is instinctive and pre-programmed by their genes. Over the years, natural selection has evolved flies with genes that keep them away from garlic-smelling plants.

There is a lot of truth in the folklore tradition that eating lots of garlic helps keep midges away. Thiols secreted through pores in your skin keep you safe from midge bites. So eat plenty of curries to keep midges at bay!

The same principle has been applied to cattle-feed. Harbro, an animal feed manufacturer, has a mill next to the M74 near Lesmahagow, where they include garlic in cattle-feed supplements. Twenty-tonne loads of human-grade, freeze-dried garlic are regularly imported from China to be included at high levels in those special cattle rations.

Cattle that are harassed by flies can't graze properly and don't grow as fast as contented animals. Another advantage of keeping flies off cattle is that it reduces the incidence of a disease called summer mastitis. It's spread by flies and affects the udders of in-calf heifers and cows that aren't producing milk, or dry cows as farmers call them. Affected dairy animals are ruined for milk production and have to be slaughtered for beef.

Another group of sulphur compounds found in garlic is allicins, which have mild antibiotic properties. Those with a strong smell of garlic on their breath obviously have lungs filled with allicins that kill off bacteria.

So another advantage of feeding garlic to cattle is that it helps to reduce respiratory problems and coughing in the autumn.

The only drawback with garlic cattle-feed is that it can't be fed to milking cows, as it taints the milk.