https://phys.org/news/2018-06-humans-monkeys-routesbut.html

"People are amazed that animals can often find the shortest route when foraging for food, and the big question is how they're able to figure it out," says lead author Julie Teichroeb, an assistant professor in the Department of Anthropology at U of T Scarborough.

"Solving these kinds of routes is extremely difficult mathematically but we've found that these monkeys, much like us, rely on heuristics."