When in Madrid ..

British worker ants are socially docile and "apathetic" compared with their "aggressive" Spanish relatives, researchers have found. Scientists from the University of Leicester discovered that the workers in colonies of twig ants choose their own queen. However, Spanish ants decided on a single queen and harassed or even killed her rivals, whereas workers of the same species of ant in France, Germany and the UK were loyal to several reproducing queens. Robert Hammond, from Leicester's department of biology, said understanding the reasons for the differences in ant colonies' social organisation could help to control invasive species.