From ants to elephants, animal actors include all kinds of species — even cockroaches. Lassie, Mr. Ed, Morris the Cat, and others work on the big screen as well as the small. The animals may act or be part of a documentary. Horses and dogs can be found entertaining crowds at circuses. Many of these animals work with trainers, groomers, and certified animal safety representatives. Then there are jockeys who ride horses, and reporters who cover the races. Not all of the animals have a starring role, but they are essential in the world of entertainment.