The stealthy little drones that fly like insects

When Storm Ciara swept across the UK in February, Alex Caccia was strolling on Oxford's Port Meadow watching birds take to the air.

He marvelled at their indifference to high winds: "While airliners were grounded by the weather the birds couldn't care less!"

It was more than just a passing thought for Mr Caccia, who is the chief executive of Animal Dynamics, a technology start-up applying lessons from wildlife to drone design.

Formed in 2015 to pursue the science known as biomechanics, his company already has two drones to show for an intimate study of bird and insect life.

One takes inspiration from a dragonfly, and has attracted funding from the military. Its four wings make it steady high winds that would defeat existing miniature spy drones.

Known as Skeeter, the secretive project has cracked the challenge of using flapping wings to power a drone. While wings are more efficient than a propeller and allow a dragonfly to hover in the face of strong gusts they are almost impossible for human engineers to emulate.

"Making devices with flapping wings is very, very hard" says Mr Caccia. Helicopters manoeuvre by changing the pitch of rotor blades to go forward and backward or to hover. For smaller objects hovering is a major challenge.

"A dragonfly is an awesome flyer" says Alex Caccia, "It's just insane how beautiful they are, nothing is left to chance in that design. It has very sophisticated flight control."

The dragonfly does have 300 million years of evolution on its side. Animal Dynamics has spent four years writing software that operates the hand-launched drone like an insect and allows it to hover in gusts of more than 20 knots (23mph or 37km/h). From 22 to 27 knots is classed as a "strong breeze".