Pitcher Plant Symbiosis
The carnivorous plant Nepenthes rajah has developed a mutualistic relationship with mountain treeshrews.
The treeshrews perch themselves on the rim of the trap and eat the nectar produced on the lid. As it feeds, it defecates into the basin.
Pitcher plants get nutrients from digesting trapped insects, and in this case shrew droppings. This is an adaptation to the nutrient poor soils which they grow in.
Chi’en Lee on Wikipedia Commons