Cages are steel; once loaded one person cannot move them — machinery is required. Main options are forklifts (counterbalanced and reach), hydraulic pallet trucks, cage carts, and battery tractors. To speed work, two cages are sometimes stacked and moved together. That is allowed, but watch two things: stay within the moving machine's rated load, and slow down in corners — a tall stack has a high center of gravity and tips on sharp turns. Three or more cages stacked for transport is banned outright. It badly damages the cage structure — the bottom layer carries two upper layers, and channel steel plus stacking feet deform easily — and a tipped load endangers people and goods.