Snails are not known for their quick thinking, but scientists in Sussex have found that they can make complex decisions using just two brain cells.
One cell tells the mollusc if it is hungry or not while the other lets it know when food is present.
The discovery, made using electrodes to measure activity in the brains of freshwater snails searching for lettuce, could help engineers design more efficient robots.
Food-searching is an example of a goal-directed behaviour essential for survival.
During such goal-directed decision making, an animal must integrate information about both its external environment and internal state while using as little energy as possible.