Okay when I was little I ALWAYS wondered what they did so I'd pull em left and right and they went "eurmbdrmmmmm" it was strangely addictive so I kept doing it until someone told me to stop, I was a little shit back then so I'd do it one more time for good measure. Only for an hour later to be back at it again, the way the plastic and tightly coiled spring moves See More▼ was great, just dont put your finger in the way as it sproings or your hand will be hurting for a while