The travelling salesman problem is a famous optimization problem where you attempt to find the shortest path in a network that touches every node exactly once. The name comes from the idea of a travelling salesman who has a list of cities to visit—ideally he wants the shortest overall trip that hits each city once. This problem is fairly trivial to solve for a small number of cities, but it quickly becomes unsolvable as the number grows larger.
Quite surprisingly, however, recent research shows that bumblebees instinctively solve this problem (the “cities” are actually flower patches in this case). The experiment was only done with four flower patches, but it’s still pretty impressive that a brain the size of a grass seed can do this at any level. The hope is that further investigation will make it possible to create better computer algorithms to handle these sorts of problems.