Humans have been using bows and arrows since the Palaeolithic era. Cave paintings in Spain show hunting and combat scenes with bows and arrows that date back approximately 15,000 years. This demonstrates that the use of bow and arrow by humans has a long history. Even in hunter-gatherer societies that exist today, people use bows and arrows as weapons. Bird-hunting (yi she 弋射) with bow and crossbow only involves adding simple mechanics to bows and arrows to increase their power. Their effects include increasing the range and improving the accuracy of shots. Prior to the invention of firearms, they were the most advanced weapons.