Life in the Undergrowth: Cricket songs

Navigation - finding their way around - is a challenging problem for robots but crickets have inspired computer scientists at the University of Stirling to come up with a new way for robots to do it. Female crickets can find male crickets by homing in on the song they sing. A cricket's ears are actually in their front legs. Sounds arrive at the ears, which being on the legs are as far a part as is possible in a cricket. The legs act as long tubes down which waves of pressure pass as a result of the sound waves hitting them. A sound on one side of the cricket arrives at the ear on that side sooner than the other ear. This turns into a different amount of pressure in the tubes on either side of the crickets head. The cricket's brain can work out locations from the pressure differences, telling the cricket where the sound is coming from.

The Stirling researchers have created a similar mechanism to work in robots allowing them to navigate towards sounds. It uses an artificial brain that works in a similar way to a cricket's to turn the pressure signals from the sound into the knowledge of where to go. It uses what is known as a neural network - a computer version of the neurons in biological brains.

In a twist on this idea researchers at Swansea and Waikato have developed a system for people to navigate by song.