Cave paintings were one of the earliest known forms of art, found across Europe, Australia, Africa and China. The paintings often depicted animals like bison and cattle that were important to early hunters and gatherers, and were believed to bring good luck or success in hunting. To create the paintings, early artists used mineral pigments ground into animal fat and applied with brush-like tools made of tied animal hair. Many of the paintings were done deep within caves, suggesting they may have had religious or social significance rather than just decorative purposes.