It’s a question that can’t help but get under your skin: Just why do we itch in the first place?

Thanks to the above video by Life Noggin, though, it’s one that doesn’t have to go unscratched. As explained by our illustrious animated narrator, though itching is related to the sensation of pain, it’s not nearly as closely tied to it as scientists previously assumed it was.

While C-fibers are the broad class of nerve fibers that regulate pain, itching and heat sensation, the slow-moving nerves that control itching are specifically attuned to the release of chemicals like histamine by our cells. When agitated by histamine and its ilk, these nerves will shoot their signals up to the brain’s somatosensory cortex, and the process of itching almost instantaneously begins soon after.

While many a disorder, medical condition or plant can cause a bout of itching, the strangest cause is undoubtedly psychological. As even the video reminds us, the mere mention of itching can send people into scratching fits. Though left unsaid, it’s theorized by some that this social itch evolved as a rudimentary means of heeding the implicit warnings made by our friends and family against parasitic intruders that might be calling our bodies home.

In other words, seeing someone scratch their arm because a mosquito bit them might have placed us on guard against our own possible mosquito bites. Others have suggested that contagious itching is merely an unexpected and annoying outgrowth of our ability to easily mirror people.

Whatever the cause, though, it’s best not to think too much on the subject. Wouldn’t want to start itching, after all.