Guinea pigs are highly social animals with complex social needs that are often unmet in single-animal housing situations.
Single-housed guinea pigs experience chronic loneliness and stress that manifests as reduced activity, bar-biting, excessive vocalization, and increased susceptibility to disease. Many owners keep guinea pigs singly out of ignorance of their social requirements rather than deliberate neglect. The suffering of socially isolated guinea pigs is genuine but often invisible to owners who mistake reduced activity for contentment. Introducing a companion transforms the quality of life for solitary guinea pigs - the behavioral change is often dramatic. Responsible pet retailers should require buyers to purchase guinea pigs in pairs and provide education about social housing.