Tiny insects that avoid light, bedbugs have folks scratching in epidemic numbers. Incorrectly associated with dirt, these critters are attracted by carbon dioxide, and they’re popping up in dorms, hospitals, movie theaters, and even swanky hotels.

Herbalist James A. Duke, PhD, suggests several botanical repellents including black cohosh (alias bugbane) and black walnut extract. “The Handbook of Spices includes a strange use for sassafras: ‘for bedsteads to keep away bedbugs,’” he adds. “My West Virginia friends mention that their grandparents put pennyroyal in the bed slats as a bedbug repellent.”