" When describing both the act of defecating and the substance of fecal matter itself, biologists prefer to use the scientific term “poop.” It’s both a noun and a verb. A popular field of biology called scatology is the study of scat, which is not to be confused with mere poop. Although technically they’re the same, we call it “scat” if we are studying it to learn something about the health and diet of an animal. When the animal has pooped on us or has ruined something with his pooping, we tend to use the term “shit,” as in, “Oh, man, he just shit down the back of my neck.” So if it’s on the ground, it’s poop. If it’s under your microscope, it’s scat. If it’s running down your neck, it’s shit. "
― , Wesley the Owl: The Remarkable Love Story of an Owl and His Girl