To make Mousterian tools, early humans used the Levallois technique. This is a prepared-core technique: the toolmaker works on the core of the stone for so that they can strike off a long, fine blade. For this quality of work, early humans had to use a 'soft' hammer made of something like deer antler, not a stone hammer. Neanderthals had larger brains than humans; this may have helped them develop Mousterian technology.