Bats and smartphones: will 'bat walks' make us love them?

New technology is helping scientists and members of the public learn about the little-understood lives of bats.

Most people have a firm view of bats: one of dislike.

People fear that bats will get into their hair, call them "rats with wings", or associate them with horror movies, vampires and other creatures of the night.

Not everyone dislikes bats, however: Prof Kate Jones is a keen bat-spotter.

To get people to share her fascination with these flying mammals, the University College London bat expert has teamed up with artist Jeremy Deller to present a series of "bat walks" in East London.

On the walks, people can learn about bats with the help of digitally generated images, which they can look at on tablets and smartphones.

"We are trying to reveal the sounds that people cannot hear," says Jones.

"Outdoors at night, bat sounds can be all around us and by using gadgets such as tablets and smartphones we can open up this world of sound to a new set of people, whom you might call citizen scientists."

Contrary to popular belief, bats are not blind - in fact many see perfectly well.

As they fly about at night, however, they need a lot more information about their surroundings than their eyes can provide. So bats have evolved to navigate and hunt by echo-location.

Bats make not only some of the highest sounds in the natural world but also some of the loudest.

The common noctule bat ( <italic>Nyctalus noctula</italic>), one of Britain's largest, shouts four times louder than the legal limit of a night club - and yet we can't hear it at all because of its high pitch.

Like birds, bats make social calls.

"If you are lucky, you can hear bat songs," said Prof Jones.

"Their little songs sound like chirrups. They are lower than normal echo-location frequencies but they are still a bit above our hearing. Kids can often hear them and women can often hear the bottom bit of the call."

Older electronic bat detectors transformed bat calls so that people could hear them, but in doing so they destroyed the original information.

New bat detection technology lets scientists study bats in much greater detail, keeping all the information about the calls' length, pitch and loudness.

Prof Jones hopes to develop something similar for non-specialists.

"You would be able to plug a microphone into a smartphone, hold up the phone and it would tell you what bat species you were listening to."

She suspects that with more understanding of bats will come more appreciation.

So the next time you see a bat flying about at the end of the day, don't shudder at these "creatures of the night".

Remember that they have no interest in flying in to your hair. In fact they are some of our best friends. "They are like an indicator of the health of the environment," says Jones. "Their calls are like its heartbeat."