No wonder dogs have earned the title of "man's best friend."
A new study published Wednesday in the "Plos One" journal found that our four-legged companions might have the ability to know when humans are stressed.
Researchers collected samples of 36 people's breath and sweat before and after doing a task.
According to the study, the animals got the emotion right nearly 94% of the time.
Previous studies conducted found that dogs can already tell when a person is scared or happy, so researchers eliminated those competing scents for this study.
Dogs have 220 million olfactory receptors, which is more than quadruples the amount humans have.
