For the time being, they can influence their behavior

Nov 16, 2007 10:00 GMT  ·  By

You cannot get rid of cockroaches that easily and they are so hardy that they are amongst the few organisms that can survive in an area after atomic experiments. The disgusting insects also surprise us with a memory that makes them capable of advanced learning. But a new toy can change their behavior. Cockroaches always look for the dark shadow of a shelter. The new robot can make them choose the wrong placement.

The tiny robots, developed by Jose Halloy, a social ecologist at the Free University of Brussels in Belgium and described in Science, smell and behave like cockroaches, changing their behavior.

If the devices lingered on more brightly lit shelter, the insects did too, a bizarre behavior for these insects. The new gadgets could explain how animals in swarms take collective decisions. Even if the devices are as big as cockroaches, they are car-shaped.

"Although cockroaches perceive light levels well, they don't recognize each other by sight. Instead, they rely on smell," said Halloy.

Halloy's team wrapped the tiny cars in cockroach-scented paper, but were programmed to act somehow after they studied the type of behavior on groups of cockroaches investigated in a test arena. The team noticed that the bugs go around randomly. When reaching darkness, they linger there, even longer if a few other individuals are already under this shelter.

That's why most cockroaches usually gather under a single shelter, even when other similar shelter is empty nearby. What's clear is that the insects prefer the darkest shelter.

The researchers observed groups of 12 cockroaches and four robots, in an area with two differently shaded zones. The robots were programmed to linger under the brighter shelter and they influenced the cockroaches which lingered under the brighter shelter over twice as often as they normally do.

"It's an interesting piece of work. They have influenced gregarious animals to change their behavior in ways consistent with the [robot] designers' intent." said Ronald Arkin, a robot swarms researcher at the Georgia Institute of Technology in Atlanta. Halloy's team will experiment with hatchling chicks, to see if they take a robot as their leader, as birds in the first days get close to moving objects, which they consider their "moms".