Artist John Knuth doesn’t actually make his paintings, which have an intriguing, almost pointillist appearance. Instead, like Damien Hirst, he lets his assistants do all the work. Except Knuth’s assistants are flies, and their work involves pooping and puking all over the canvas. Art!

Flies spend most of their time walking around on their food, vomiting digestive juices on it to turn it into edible liquid (flies can’t eat solid food, as they don’t strictly have mouths). Puking all the time means they have to work hard to keep hydrated, so they pee all the time too. That means they make terrible roommates, and that you probably shouldn’t eat something a fly walked on extensively, but it also means that if you feed flies colored water and set them loose on a canvas they will poop-puke you a beautiful painting. Which is exactly what Knuth does.

I’m not sure I’d want to own one of these canvases, but they have a couple of things going for them: They are actually really interesting-looking as modern art, and they make museum guards’ jobs pretty easy. When the little card says “materials: fly puke and poo,” who needs to be told not to touch?