Food and Water Dishes
Obviously you need dishes for water and food in your rat's cage. There are a lot of different dishes you can use, so here are some tips:
Look for ceramic or locking food dishes
Why? Rats like to sit in/on the food bowl when eating, which means that if it is not heavy ceramic or locked to the cage, it will tip over and there will be a big mess of food everywhere. Trust me, this happens a lot at the shelter. Another plus is that ceramic food dishes are really easy to clean.
If you can, get two food dishes
Why? Rats benefit from small amounts of fresh veggies and treats like whole wheat cereals and crackers. If they don't eat them right away and extra bowl comes in handy.
Make sure the bowl is big enough.
Why? How big is "big enough"? As I mentioned before, rats like to sit in/on the food dish. The dish should be big enough to fit the proper amount of food and the bowl should be large enough that the rat can sit on it, they seem to like eating that way the most. If the bowl is too small, they will most likely knock it over.
Look for bottles, not bowls.
Why? Using bowls for water is not practical for rats. They may knock it over, which means they will have no water. Water bowls also get dirty very easily. Rats like to play with everything, which may include a water bowl, which will result in a mess. A water bottle is generally more practical, clean, and easy to use. The only small pet that I would use a bowl for is a rabbit, because many rabbits prefer to drink out of a bowl. Rats however, will gladly drink out of a water bottle.
Make sure the bottle is big enough.
Why? How big? The "why"is pretty obvious; you need to have enough water for each rat. You should have at least eight ounces or more water per rat, so make sure the bottle holds enough, and if not, get a second bottle and so on, until you have enough.
Tip: Generally a guinea pig water bottle (usually sixteen ounce) is enough for two rats, and a rabbit water bottle that is 32 oz, is enough for four rats. So looking for guinea pig or rabbit water bottles is a good idea. Rat and mouse water bottles generally only hold enough water for one rat.
Tip: Sometimes rats like to drink at the same time. Sometimes that leads to squabbles. If your rats are fighting over the large group water bottle, get one smaller water bottle for each rat, so that there is always a water bottle available for each rat.
(I haven't seen many rats with this problem, but it does happen occasionally)
Tip: A good brand of water bottle to buy is SuperPet. In all the water bottles that I have dealt with at the shelter, the SuperPet ones leak the least or not at all. Also if you shop at Petsmart avoid the cheap "All Living Things" water bottles. The shelter has had quite a few and most of them are now in the trash because after a while all the water leaks out.