Do you know when the first computer mouse appeared? It happened more than 50 years ago. The first computer mouse was publicly presented on December 9, 1968 by Douglas Engelbart. Earlier, he also had built built the first mouse prototype in 1964. The invented device had a wooden case with wheels inside and a long wire which looked like a tail. Douglas and his colleague Bill English were the people who named the device "mouse". However, it wasn't was not the only invented device at that time. On October 2, 1968 a German company presented another mouse-like device. It was named Rollkugel, which means a "rolling ball" in German. It had the shape of a half ball and made contact with the working surface using a trackball inside.