Dragonflies evolved around four hundred million years ago, predating dinosaurs, lived through the age of T.Rex and are still with us today virtually unchanged apart from a marked difference in size.

For in those far off days the wingspan of dragonflies measured a formidable eighteen inches, made possible by a greater concentration of oxygen in the atmosphere that allowed many creatures living then to attain a larger size.

Over millennia, nature sometimes dispenses with species that may prove inefficient but with dragonflies their design was absolutely right, hence their longevity.

Equipped with huge globular eyes they can fly forwards, backwards, up or down and hover, catching prey in mid-air using forward-pointing bristly legs to form a kind of fishing net into which they scoop up prey as large as butterflies. I have even seen a dragonfly speed into a garden spider's web and pluck out the female spider perched in the centre.

Dragonfly nymphs live under water for two years feeding on tadpoles, small fish and invertebrates. These are stalked and when close, the nymph shoots out a jet of water from its rear end rather like a miniature rocket motor and pounces on the hapless creature.

Dragonflies lay eggs into waterside trees  but sometimes mistake the legs of horses and cattle standing in shallow water for logs or vegetation.

Long ago, farmers witnessing this wrongly thought their animals were being 'stung' so called dragonflies 'horse stingers'! But dragonflies cannot sting.