This project explores human-animal coexistence through scalable modular design. A 450mm-high base unit, ergonomically contoured for humans, incorporates ellipsoidal substructures creating interconnected caves for small animals. Modules extend horizontally at 120-degree angles and vertically via mirroring, forming adaptable spaces: aggregated units become human furniture (chairs: 450mm, counters: 1350mm) while internally housing spherical nests. Two fabrication methods are proposed: CNC-carved wood and recyclable EPP foam. The system allows dynamic configurations – from urban furniture to permeable walls – maintaining species-specific dimensions (animal caves vs human 900mm sills/1800mm height ranges). This symbiotic design enables physical interaction while respecting both species' spatial needs through geometric transformation, creating shared yet distinct habitats in a single structural system.