How crickets don't get stumped in the night

A ROBOTIC cricket with ears in its legs has been built by scientists who hope it will help them understand how its real-life equivalent finds a perfect partner.

Nottingham University psychologist Barbara Webb is one of a team of three from Nottingham and Edinburgh universities which has built the female cricket robot.

In nature, male crickets sing to attract females. Crickets have their ears in their front legs, which gives strong directional hearing.

Females of certain species can hear songs at a range of frequencies, but only respond and head for a male producing a song of a specific frequency. In this way females only head for males of the same species.

How crickets distinguish the frequency of the sound, and thus a suitable male, from other frequencies has remained a mystery. According to Dr Webb, scientists understood how crickets' ears worked but suggested that there had to be some sort of neural process in the brain to filter out the other frequencies of sound.

Now the robotic cricket has shown that this may not be the case. Dr Webb's model, which uses microprocessors to imitate the natural crickets' ear and reactions, suggests that rather than a filter in the brain, the frequency to which a cricket responds may instead reflect the distance between its legs, and therefore, its ears.

It is thought that the distance between its legs needs to be a quarter of a wavelength of the note produced by a male to allow a female to pick it up. The model heads straight for a real-life male cricket when its ears are placed a quarter of a wavelength apart.

The robot cricket is one of hundreds of robotic creatures great and small which descended on Brighton this week for the fourth European Conference on Artificial Life, being held in Britain for the first time.