Do Plants Poop?

Taro Gomi's timeless classic, Everyone Poops, is a perfect example of truth in advertising. The book's cover even shows "everyone:" a rosy-cheeked child, a horse's behind, a bird, apple with a bite taken out of it? Wait, what? Do apples poop after being bitten? The bigger question, perhaps, is this: do plants poop? 

Even if you spent all of your high school biology lessons in a boredom-induced stupor, you're probably sure you've never seen a flower squat down and pinch a loaf. Then again, if plants do a version of dropping the kids off at the pool, it won't look like what humans doo. As with any organism, it depends on the plant's anatomy and how it digests its version of food.

Science teaches us that plants are autotrophs, meaning they "produce [their] own food using light, water, carbon dioxide, or other chemicals." Through a process known as photosynthesis, plants convert those various ingredients into a type of sugar known as glucose. During meal time, a plant discards oxygen, water, and other substances, raising the distressing questions of weather humans breathe plant poop (oxygen) and drink plant pee (water).

Reassuringly, Popular Science says that humans don't breathe plant poop. The oxygen they expel is more like the plant exhaling — or as we like to think of it, belching. As for the water, well, that might be akin to a plant's pee or at least its sweat. A plant's version of pooping might be excreting excess salt, metals, and other substances absorbed through the soil. In trees, those waste materials may become bark, meaning trees basically soil themselves. Plants also expel methane, which you could construe as foliage farting.

Of course, not every plant gets food exclusively through photosynthesis. Venus flytraps trap flies, obviously, and "birdcatcher trees," like their name implies, catch and kill birds, which get stuck in their ultra-sticky sap. Luckily for our squeamish human brains, these murderous plants didn't develop animal excretory systems. In the case of Venus flytraps, those Little Shop of Horrors-looking beasts liquefy parts of the fly with special enzymes and then open back up and release the bug's desiccated remains. So it sort of poops dead flies. With respect to birdcatcher trees, sometimes their winged prey just gets stuck in the branches and becomes petrified like mummies. So basically, these trees poop nightmares.