London - When we see their spindly legs scuttling across the floor, many of us quake with fear.

Scientists believe they may have worked out why we fear spiders more than other creepy-crawlies.

Psychology professor Jon May says their angular shaped legs, dark colours and the fact they move unpredictably are all things we are hard-wired to fear.

He said studies have shown that people tend to dislike angular shapes and prefer curved ones, have bad associations with dark colours, and prefer creatures we feel we can “understand”.

Professor May, from Plymouth University, added: “Spiders just tick all these boxes, and like any phobia, when it builds up in someone’s mind they can become scared even seeing a picture. We like bright- coloured butterflies and ladybirds, but spiders are dark coloured with long angular legs – and the shape and colour both have strong negative associations.

“We are also very sensitive to seeing things moving out of the corner of our eye and immediately notice it, and insects move quickly and unpredictably. People scared of spiders will often report them being bigger than they were or say they saw one crawl into someone’s mouth, which spiders never do. We don’t understand their behaviour.”

Professor May said fear is also ‘socially conditioned’, which means we are more likely to develop it as children if we encounter it at home from our parents or siblings.

He added that arachnophobics can be deal with their fears by trying to sympathise with the insects and learn about them.

He and Dr Adam Hart, a reader in science communication at the University of Gloucestershire, are to hold a public session at Cheltenham Science Festival looking at the reasons people fear insects.

Other people have phobias about insects such as moths, beetles and cockroaches.

Dr Hart said small children are happy to handle creepy-crawlies in the garden and find them fascinating, but become scared of them as they get older.

He said one of the ways to learn to appreciate them is to eat them – and he will be cooking a mealworm stir fry for visitors to the festival. - Daily Mail