Bacteria can develop antibiotic resistance quickly through their ability to reproduce rapidly and exchange genes with other bacteria. The overuse and misuse of antibiotics applies evolutionary pressure that allows resistant bacteria to multiply, passing their resistance to other species. Within 20 years of an antibiotic's introduction, bacterial strains have often evolved resistance to it. The rise of resistant pathogens is exacerbated by incomplete treatment courses and the use of antibiotics for non-bacterial infections, as it kills benign bacteria and allows resistant strains to flourish.