The Australian Cattle Dog (ACD), or simply Cattle Dog, is a breed of herding dog originally developed in Australia for droving cattle over long distances across rough terrain. However, it is reserved with people it does not know and naturally cautious in new situations. Its attitude to strangers makes it an excellent guard dog when trained for this task, and it can be socialised to become accustomed to a variety of people from an early age as a family pet. It is good with older, considerate children, but will herd people by nipping at their heels, particularly younger children who run and squeal. By the time puppies are weaned, they should have learned that the company of people is pleasurable, and that responding to cues from a person is rewarding. It remains, however, that Australian Cattle Dogs generally age well and appear to live on average almost a year longer than most dogs of other breeds in the same weight class. With his partners, he bought several dogs and started breeding them.