Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap.
Symbiosis is the interaction between two different organisms living in close physical association, typically to the advantage of both.
In a bizarre example of a symbiotic relationship, tiny bats in Borneo have been found using a carnivorous plant as a toilet, feeding the pitcher plant with their droppings, while they safely roost in the plant’s traps.
It seems the plant has adapted to stop the winged critters from tumbling down into the bottom of the trap and drowning in the digestive fluid. The vine’s pitchers have a tapered shape and an unusually low amount of fluid, to stop the bats accidentally becoming dinner. That also prevents the bats from eating the insects that the plant catches.