The rat-bots currently just skitter around the floor, just like a rat would, with the neurons helping them to avoid walls. The team claims that the obstacle avoidance shows improvement over time, but one creepy facet of the research is that different rat brains behave differently. As each set of brain cells only lasts three months, several brains have been used – and each exhibits different behaviour patterns to the others. (Brain cells of rats used within experimental robots via Marginal Revolution)