Any pet, big or small, requires a steady supply of clean water to stay healthy. For smaller pets that can be kept in a cage, there are a variety of water bottles designed to be clipped directly to the cage. The pet's owner simply needs to fill it up, and then the pet has access to a regular supply of water whenever it needs it. The bottles can be easily attached to the cage with an accompanying clip.
Unpack the water bottle from its packaging. Take care not to destroy the outer packaging, as it likely includes specific instructions on how to attach that particular model of bottle to the cage. Unscrew the nozzle from the top of the bottle.
Fill the bottle with water. Regular, room temperature water from the tap is sufficient. Reattach the nozzle after filling it.
Place the bottle on the inside of the cage, with the nozzle facing downwards for easy access.
Attach the bottle to the side of the cage using the clip that runs along the backside of it. The exact position and type of clip will vary from model to model, but generally there should be a clip that can be attached to the wall of the cage, holding the bottle secure.
Monitor the bottle periodically to make sure it remains upright and is not dislodged by the pet.
To protect the bottle from being chewed on by pets like hamsters, small cages can be purchased that fit around the bottle, while leaving the nozzle exposed for easy drinking. If you find the bottle covered in small tooth marks, such a cage might extend the lifespan of the water bottle.