Here's why:
* They primarily get their fluids from their prey: Red-bellied black snakes are carnivorous and consume frogs, lizards, birds, and small mammals. These prey animals contain a significant amount of water, which the snake absorbs through its digestive system.
* They can absorb moisture from the environment: They can also absorb moisture from damp soil or vegetation.
* They are efficient at conserving water: Snakes have scaly skin which prevents water loss, and their kidneys are designed to conserve water.
While they may occasionally drink water if available, it's not essential for their survival.