Insects surround us in astonishing variety and diversity but few of us take much notice of them except when there’s a spider in the bath or a wasp on our picnic. Yet many more of the insects that occur in our homes and gardens are beneficial rather than harmful and it’s not just butterflies that are pretty.

Take dragonflies for example. They are totally harmless, don’t possess a sting and won’t bite or attack. There are around 120 species in Europe but only 38 species breed in Britain, several of which may well occur in your garden. Look out for the emperor, our largest species and one that is widespread in southern England. Its agility and aggression are unequalled by any other British species.

Most insects reach their greatest diversity in the tropics which explains why only 34 of the world’s 1,300 species of earwig occur in Europe, and a mere four in Britain. But those four are intriguing creatures. Earwigs are one of the few insects where the females guard their eggs (nearly all others insects simply lay them and leave them). Some earwigs even look after their young until they are well grown.

There are more than 300,000 species of beetles. We have 4,000 in Britain varying in size from tiny ladybirds to the huge stag beetle, the latter instantly recognised by its size and antlers. The antlers are really jaws and are used for fighting rival males. The presence of stag beetles in your garden is a sign of a healthy environment.

Not many of us like flies, and with good reason since they are carriers of disease. However, even blow flies and house flies do an important job by breeding in decaying flesh and dung and so helping to keep the countryside clean. Don’t forget, too, that many of our most attractive birds depend on flies for their diet. For example, as soon as farms convert from livestock to arable there’s always a sharp fall in the number of nesting swallows since the latter depend on the insects attracted by cattle and sheep.