Training a lion or a tiger begins with a simple rule: Keep out of the line of fire when the animals urinate.
Alexander Lacey, the big cat trainer for the Ringling Brothers And Barnum & Bailey Circus, was lucky enough to learn that lesson from his dad, who started training the animals more than two decades ago when he owned two zoos in England.
"My father began to train the animals in his zoo, because he felt they needed something more to do during the day and the training was a great way of keeping [himself] mentally and physically challenged," he told The Huffington Post before a performance in San Diego.
One mental challenge that both Lacey and his Dad faced was keeping from laughing when one of the lions he was training started urinating on a paying customer.
"It was during a part of the show when he put his hand in the lion's mouth," Lacey laughed. "The lion started peeing for three or four minutes right on to this prim and proper, very English lady."
"The lion was peeing on this lady, but she was so prim and proper that even though the audience was laughing, she refused to get up. She ended up soaking wet and my mother had to get her a towel."
Lacey has never forgotten that moment, even as he tours the world with Ringling Brothers and his own menagerie of lions and tigers. It's a job that requires him to understand his animals on an intimate basis -- especially, it would seem, when they have to answer nature's call.
"We get to know the animals so well that it's difficult for an outsider to understand how you can judge every single movement or quirk," Lacey said. "Each animal has its own personality. People ask, 'How long does it take to train a lion? How long does it take to train a tiger?' They're like people. They all have their own personality and they're all good at different things."
GALLERY: ALEXANDER LACEY
"Some are good at jumping, some are lazy and don't want to jump and some are good at walking on their back legs."
To control the animals, Lacey uses two sticks (he prefers the term "guiders"). The one in his left hand usually has raw meat on it during the early stages of training.
"We teach them to follow the guider in the left hand," he said. "It's similar to how the donkey follows the carrot -- the lion or tiger follows the piece of meat."
The sticks are not used to hurt the animal in any way.
"The animals must not be afraid of the guides," he said. "They are simply to communicate and nothing else."
Although some animal trainers have been accused of using fear and abuse to train their animals, Lacey said that for him, that's not effective.
"The lions and tigers have to keep their own personality. That's what gives them confidence," Lacey said. "A confident animal is easy to train."