Mustangs are also known as 'mestengos'. This is Spanish and means something like 'wanderers'. These are the horses that the Spanish brought to America on their ships in the 16th century and ran away there. They were able to multiply quickly because they found abundant food on the fertile grasslands and had no natural enemies, except for the cougars. Even today there are herds of wild mustangs that roam the countryside. The bravest stallion is the leader. He protects the herd and is also usually the father of all foals.