Respect the Rex Push and Chew
A Rex rabbit brings real strength in his hindquarters and a persistent, intelligent style of exploring. Where a lighter rabbit might accept a pen panel, a Rex may lean his weight into it repeatedly, shift it a little at a time, and widen a corner until the gap is usable. He may also chew skirting, door edges, and the lower rails of furniture, so escape-proofing for this breed is about weight, latch quality, and chew resistance rather than simply putting a barrier in place.
Walk his exercise room looking for anything that moves when you push it at rabbit height. If you can shift it with one hand, assume a determined Rex can shift it during an unsupervised hour.
Anchor the Pen and Upgrade the Latches
Set his pen on a surface it cannot skate across, join every panel firmly, and add weight or secure fixings where the manufacturer's design allows them. Replace any hook or clip he can lift by nudging from below with a latch that needs a deliberate human hand movement to open. Check the door of his main enclosure the same way, and listen for rattling when he pushes it, because rattle usually means play in the join.
Keep boxes, tunnels, and houses away from the pen edge. A Rex is an able jumper when a piece of furniture gives him a higher start, and a solid hide placed beside the barrier can quietly become his step out.
Seal the Room Beyond the Pen
Block the spaces behind washing machines, cookers, and large bookcases with solid material fixed so it cannot be dragged forward. Fill or cover low gaps at the backs of cupboards, and keep bathroom and kitchen doors closed during his exercise time unless those rooms have been checked at floor level too. Rex rabbits are drawn to the cool, dark space under appliances, and reaching a trapped rabbit there without hurting him is difficult.
Store cleaning products, laundry items, and rubbish behind latched doors. If he does break out of the pen, the room itself should still contain nothing that can poison him or block his gut.
Give the Chewing Somewhere Better to Go
The Rex love of texture includes that famously soft coat and, unfortunately, your wooden furniture legs. Wrap or shield exposed edges in his area, route cables through rigid covers, and raise trailing leads out of reach. Then make the legal chewing genuinely attractive: untreated wooden toys, willow pieces, cardboard castles with no tape or staples, and fresh hay pushed into tubes he has to work at.
Rotate those pieces so the room keeps changing for him. A bored Rex tests barriers harder, while a rabbit busy dismantling a cardboard castle in the middle of the room is spending that persistence where you want it.
Handle Doors, Hallways, and Handling
Never let him free-roam a hallway that leads directly to the front door. Keep an internal door closed between his exercise space and any outside door, and bring him back to his enclosure before parcels, guests, or children's friends start moving through the house. For moves between rooms, a closed carrier prevents the sudden kick and twist that can free a strong Rex from someone's arms on the stairs.
If he escapes indoors, close exterior doors first, then narrow the search room by room, shaking a familiar food container softly rather than cornering him. Prepared in advance, KinsLe's Lost Pet Alert System lets you alert nearby members at once and receive a direct message from anyone who finds your Rex outdoors.