The humble cockroach can display surprisingly complex personality traits, according to research conducted in Belgium. Matthew Stock reports.
You might have more in common with the much-maligned cockroach than you'd like to admit. Researchers from the Free University of Brussels found cockroaches have personalities and even display different character traits, such as bravery and shyness. Lead researcher Issac Planas said the pests make perfect test subjects because of their well documented decision-making abilities. (SOUNDBITE) (English) LEAD RESEARCHER ON COCKROACH PROJECT AND PHD STUDENT AT UNIVERSITE LIBRE BRUXELLES, ISAAC PLANAS, SAYING: "Cockroaches are a simple animal, but they can reach a complex decision. So with little information, with little interactions, only knowing if I have a partner here or not, only with this information, they can make complex decisions." At least 300 specimens of Periplaneta americana - or the American cockroach - were examined over three months. Tiny microchips were attached to their backs. When placed in a brightly lit arena containing two round shelters, scientists monitored how long it took the roaches to hide underneath. Some insects took cover as soon as they entered the arena while others spent more time exploring - a trait consistent in each test. What surprised Planas the most, was that every cockroach eventually ended up under the shelter. (SOUNDBITE) (English) ISAAC PLANAS, LEAD RESEARCHER ON COCKROACH PROJECT AND PHD STUDENT AT UNIVERSITE LIBRE BRUXELLES, SAYING: "The fact, and we didn't expect it, is that they always reach this consensus. So we expected that some groups have more trouble than others to resist consensus or to choose a shelter, but at the end, no, they always finish aggregated. So it is something really inside the individuals or the cockroaches. So that was really, that was amazing." The differing personalities could explain the dark-loving insects' reputation as one of nature's great survivors; with bolder cockroaches venturing into new environments, while more cautious ones remain behind to check the surroundings are safe. The researchers now plan to analyse how individual cockroach behaviour and learning affects the group mentality.