I thought this was already known. I remember watching a show a few years back on Neanderthals that mentioned they used a form of glue. For context, if anyone else might recall this show, a researcher attempted to recreate the "spearhead" they found and determined it was more sophisticated than previously thought. They also had shared results of DNA sequencing which found a 98%+ similarity to homo sapiens. Unfortunately, I don't remember where I saw it, or what it was called.