Water Bottles
It's important that your rats always have fresh water available. Water bottles are a great option because they are a clean, spill proof way to provide water for your rats without dust and other contaminants. In my experience, it's a smart idea to have multiple bottles in the cage in case one becomes empty or stops working. A good rule is to have one water bottle per level, or per rat.
Glass vs Plastic
Glass bottles are chew proof while plastic bottles are not. I personally don't have any issues with rats chewing the plastic water bottles, although it can happen. I use both glass and plastic bottles.
Kaytee Chew Proof Bottle
Lixit Water Bottle
Glass Water Bottle
Kaytee Clear Bottle
Pet Lodge Bottle
Food Bowls / Dispensers
Unless instructed by a veterinarian, rats should have access to a quality lab block at all times (for help choosing a healthy food for your rat, click here). Ceramic bowls are most commonly used with small animals because the weight makes it difficult to tip over, it cannot be chewed, and it is easy to wash. If a rat doesn't know how to properly use a water bottle, a bowl of water can be used instead.
If your rats insist on tipping their bowls, there is a great option. You can purchase a bowl that attaches to the cage. While this does make it nearly impossible for them to tip, it doesn't prevent spills and other messes. They're still rats, of course!
Living World Dish
Kaytee Stonewear Bowl
Snap'y Fit Bowl
Unlike other animals, rats will stop eating once they're full. That's why it's important to keep food in their cage at all times. If you have to go out of town, you can use a food dispenser to ensure that your rats won't go hungry while you're away.
Little Giant Metal Dispenser
WATER BOTTLES & FOOD BOWLS
Living World Bottle
Stainless Steel Bowl
Prevue Bin Feeder