Free-roam is the best part of rat keeping and the easiest way to lose a rat behind a kitchen unit. Rat-proof the room before the first session, not after the first escape. Cables: box them, run them in trunking, or unplug and remove them. A chewed live cable is a fatal risk and rats find them fast. Gaps: block the space under doors, behind and under sofas, beds, wardrobes, kitchen units and radiators. A rat can pass through a gap the width of their skull, roughly 2.5 cm for a large adult. Check for holes behind furniture and around pipework. Choose a safe play zone: a cleared bed can make a comfortable supervised play area. Protect bedding with a washable cover and keep rats away from the edge, headboard gaps, electrical cords and anything unsafe underneath. A dry bathtub lined with blankets, a hallway, or a fully rat-proofed room can also work. Barriers: modular pet playpen panels or tall, smooth-sided barriers arranged like a baby fence can create a larger safe area. Rats climb mesh and can jump surprisingly well, so use smooth panels tall enough for your rats, close every gap, brace the panels, and supervise throughout. Ordinary baby gates are often climbable and their openings may trap or release a rat; cover them with a securely attached smooth panel rather than relying on the bars. Toxins: remove or move houseplants, cleaning products, medicines, pesticides, poisons, snap traps and anything left out that could be chewed. No candles, diffusers or aerosols while rats are out. Other pets: dogs and cats do not get supervised access, full stop, no matter how gentle they are. Set up the space: tunnels, cardboard boxes, a dig tray, ropes, hides, a shallow pea-fishing bowl and scattered food make exploring worthwhile. Rotate the layout and add safe climbing routes. Sit on the floor or bed so you become part of the furniture rather than a looming hand. End sessions with a routine: a treat in the cage, the same phrase every time, or a target box they return to. Count your rats going out and coming back in, every single time.