Designer Dogs have Moderate Physical Traits. Each purebred has its own unique set of physical characteristics. In some cases, these traits have been emphasized to the point that they frequently cause health problems for the dogs of that breed. For example, some dog breeds, like Bulldogs, Pugs, and the Pekingese, have such short noses that it causes breathing difficulties. In some breeds, these physical characteristics are so exaggerated and create such health problems that if the dogs were wild, these traits would likely be considered a deformity. Crossbreeding tends to reduce these extreme physical features assuming the two breeds chosen for crossing to not share the same exaggerated features. Designer Dogs have Moderate Behaviors. In addition to a more moderate appearance, designer dogs often have more moderate behaviors than purebred dogs. The majority of purebred dog breeds were developed to assist man with some particular task. Because we are now converting this task-oriented animal to a companion animal, some of the original behaviors for which the breed was created are now sometimes viewed as preventing the animal from being well-suited as a household pet. Because designer dogs are a mix of two purebreds, extreme behaviors tend to be averaged between the two breeds involved with the cross. For example, a dog bred to assist with herding sheep, such as a Border Collie, may not be appropriate for a household with children. In addition to needing several hours of daily exercise, Border Collies may attempt to herd children and may nip or headbutt if the children resist being herded. Crossing a Border Collie with a lower-energy dog may result in a puppy with a more moderate activity level and chase instinct, instead of the virtually obsessive chasing and herding behaviors that a purebred Border Collie typically displays. Reducing the strength of strong genetically-based behaviors helps to create a more moderate temperament; a temperament that many pet dog owners are frequently more interested in.