Pet rats are highly intelligent, social animals whose welfare depends critically on living in pairs or groups, having sufficient space and enrichment, and receiving regular human interaction.
Rat welfare is most commonly compromised by solitary housing and inadequate cage size. Rats in isolation show measurable immune suppression and altered neurochemistry - genuine physiological consequences of a fundamentally social animal being denied companionship. Cage size is also critical - rats in small cages cannot express climbing, nesting, and foraging behaviour. Respiratory disease in rats is progressive and requires veterinary treatment - many owners delay seeking care because 'it's just a rat.' Rats are intelligent enough that boredom causes real welfare harm; daily interaction and foraging enrichment are not optional extras.