Horses are trained and ridden for practical working purposes, such as in police work or for controlling herd animals on a ranch. They are also used in competitive sports including dressage, endurance riding, eventing, reining, show jumping, tent pegging, vaulting, polo, horse racing, driving, and rodeo (see additional equestrian sports listed later in this article for more examples). Some popular forms of competition are grouped together at horse shows where horses perform in a wide variety of disciplines. Horses are used for non-competitive recreational riding such as fox hunting, trail riding, or hacking. There is public access to horse trails in almost every part of the world; many parks, ranches, and public stables offer both guided and independent riding. Horses are also used for therapeutic purposes both in specialized para-equestrian competition as well as non-competitive riding to improve human health and emotional development.