Guinea pig varieties found in pet stores are the English shorthair (also known as the American), which have a short, smooth coat, and the Abyssinian, whose coat is ruffled with cowlicks, or rosettes. Also popular among breeders are the Peruvian and the Sheltie (or Silkie), both straight longhair breeds, and the Texel, a curly longhair. Grooming of guinea pigs is primarily accomplished using combs or brushes. Shorthair breeds are typically brushed weekly, while longhair breeds may require daily grooming. Cavy clubs and associations dedicated to the showing and breeding of guinea pigs have been established worldwide. The American Cavy Breeders Association, an
Rock cavy and the mediodorsal nucleus, a large nucleus in the thalamus, which may provide the rock cavy with strong emotional learning, visual recognition, and object-reward association memory. This may explain why the animals are found to live in large groups. They can sometimes display homosexual behavior, with males courting males. Some paedophilical behavior has also been displayed, with adult males courting juvenile males. Each group has an alpha or dominant male and several females. The males are territorial, defending rock pile shelters against other adult males. These rock piles are built to impress the females. Once a females chooses a rock