Why do dogs sniff other dogs butts?

When dogs sniff each other's butts, they aren’t just huffing stale fart fumes, but “speaking with chemicals,” as the American Chemical Society puts it. A dog’s sense of smell is 10,000 to 100,000 times better than ours thanks to its large olfactory membrane, a lump of tissue tucked up in its snout that can be as large as a handkerchief and hold more than 225 million olfactory receptors. read more

The answer to that question is a bit more complicated than you might imagine. According to a new video from the American Chemical Society (above), it's all about one canine literally sniffing out important information about the other--its gender, emotional state, diet, and more. read more