Neanderthals may have used birch tar as more than just glue; it could have helped them ward off infection and even insect bites. People from several modern Indigenous cultures, including the Mi'kmaq of eastern Canada, use tar from birch bark to treat skin infections and keep wounds from festering. We know from several archaeological sites that Neanderthals also knew how to extract birch tar and that they used it as an adhesive to haft weapons. A recent study tested distilled birch tar against the bacteria *S. aureleus* and *E. coli* and found that Neanderthals could easily have used the same material as medicine for their frequent injuries. This is the simplest step-by-step tutorial for making birch tar: find a tree, set some bark on fire, get messy hands.…