The search for the right bit is an ancient one. Archeologists now speculate that humans probably became equestrians at least 6,000 years ago, and riders have spent the intervening millennia trying to figure out how best to communicate with their horses. Early bits were made of vastly diverse materials, such as animal horn, bone, wood, sinew, rawhide, and rope. The appearance of metal bits coincides with the Bronze and Iron Ages, roughly the time between the 8th and 14th centuries BC.