If I started talking about creepy-crawly spiders and ants, would you feel itchy, and start scratching? You’re not alone. The truth is, seeing, discussing, or even thinking about insects makes most people feel itchy all over, and the experts can’t seem to agree on why. Neuroscientists from the University of Pennsylvania believe the phantom itching is caused by previous itchy experiences, and the memories of having to scratch away bugs, leaves, and stray hairs.

But Dr. Glenn Giesler, Jr. is a neuroscientist from the University of Minnesota, and he believes we always have tiny sensations on our skin that feel slightly itchy, but we only notice them when we’re thinking about the feelings - or about the creepy-crawlies that can cause them. In fact, whenever Dr. Giesler gives a lecture about itching, he’s amused because most of the audience starts scratching.

But another expert thinks that itching is mostly mental. Dr. Gil Yosipovitch is the founder of the International Forum for the Study of Itch, and he points out that itching is contagious. You may not actually feel itchy, but when you see someone else scratching, you scratch too. He says it’s a subconscious behavioral response similar to contagious yawning and it’s a primal way to connect and bond with others by mirroring their actions.