Here's why:
* They need water: Platypuses are excellent swimmers and rely on water for hunting, cooling down, and raising their young. Deserts lack the consistent water sources they need to survive.
* They need specific food sources: Platypuses primarily feed on aquatic insects, worms, and crustaceans. Deserts lack these types of prey.
* They need specific habitat: Platypuses build burrows in the banks of rivers and streams. Deserts lack the suitable soil conditions for burrowing.
In short, platypuses are perfectly adapted to their wet, watery environment. They would not be able to survive in the harsh conditions of a desert.