Neanderthals created stone tools held together by a multi-component adhesive, a team of scientists has discovered. The astonishingly well-preserved tools, more than 40,000 years old, showcase a technical solution broadly similar to examples of tools made by early modern humans in Africa. Its findings, which are the earliest evidence of a complex adhesive in Europe, suggest these predecessors to modern humans had a higher level of cognition and cultural development than previously thought. The stone tools from Le Moustier — used by Neanderthals during the Middle Palaeolithic period of the Mousterian between 120,000 and 40,000 years ago — are kept in the collection of Berlin’s Museum of Prehistory and Early History and had not previously been examined in detail. The tools were rediscovered during an internal review of the collection and their scientific value was recognised. The researchers discovered traces of a mixture of ochre (over 50%) and bitumen on several stone tools. Using liquid bitumen with 55% ochre, researchers were able to produce a mixture that was sticky enough for a stone tool to remain together but without adhering to hands.