Choosing and finding a proper rat cage can be tricky. Hopefully this post makes it a little easier.
Here is what to look for when choosing a rat cage:
A wire cage with horizontal bars
Why? Wire cages provide proper ventilation and rats LOVE to climb so horizontal bars are a major plus! A wire cage is generally a better option than a tank/aquarium. Tanks do not provide enough ventilation, (they start to STINK very quickly!), and no climbing.
Solid flooring and shelving
Why? As with all small pets, wire floors and shelves cause sores on the bottoms of a rat's feet.
How much is adequate? That depends on how many rats. The MINIMUM for one (maybe two) small rats is two square feet of floor space and plenty of vertical space. A cage with three feet by two feet of floor space (six square feet) and two to three feet of vertical space is better. And remember the more rats, the bigger it needs to be!
Why? Rats are climbers and should have more than one level in their cage.
Proper Bar Spacing
What is proper bar spacing? Rats can squeeze through TINY spaces. For small or juvenile rats the bars should not be spaced out more than a half of an inch. Large adult rats may be able to he housed in a cage with one inch bar spacing, but smaller rats can possibly squeeze through that. And definitely nothing bigger than one inch spacing or you will have a rat on the loose!
And now for some important "niceties" (not necessities, but some features that are nice)
Escape proof/locking doors
Why? Rats are smart!
This is for you, not the rats. Trust me, small doors are a PAIN. It is hard to get to the rats and to clean the cage with small doors.
This a plus for the rats and you. Rats are more comfortable in a cage that is up off the floor. Many cage stands have a shelf which provides storage space for you. Of course, you could also place the cage on a table or something instead of using a stand.
Some cage brands and my reviews: (you can click the links below each description to see pictures of the cages)
Super pet rat cages: Most of these are too small for rats. However, their "exotic pet cage" is large enough for a couple of rats. However, I find that the cage is a hassle to clean. The shelves cannot easily be taken out through the tiny doors, the shelves have a sort of "moat" around the edge that gets really dirty and is hard to clean, the small doors mean that you must take the top off the bottom to easily clean the whole cage. So while it is large enough it is very inconvenient. It is also rather pricey for its quality.
Super Pet Exotic Deluxe cage
Ware cages: Most are too small. The natural cage is adequate for one rat or temporarily for two or more juvenile rats, but the shelves are made of wood. And that is nice for the rats to chew, but they get really dirty and can't really be cleaned.
Ware Wood rat cage
Prevue: Prevue has a very nice rat cage... no actually it is a rat mansion... RAT HEAVEN!!! It is huge, has two upper levels, and some pluses for the owner: a slide out pan, a locking large door, a stand with a shelf. This is the dream home for rats! Just do not use the removable wire floor grate unless you cover it with a solid surface. The only setback to this cage is that it is the most expensive cage on the market, the cheapest I have seen is 160 dollars, but in may opinion it blows most of the other cages away!
Prevue Rat Cage
Critter Nation: This cage is made by midwest and is very similar to the Prevue cage. It is really big like the Prevue cage, has a slide out pan, HUGE doors (the whole front is basically two doors), locking mechanisms on the doors, and it has a stand with a storage shelf. The only difference is that it has one upper level as opposed to two. It is pretty pricey, but cheaper than the prevue cage and definitely worth the cost. Another plus is that you can purchase an add-on to double the space if you want more rats. It can be purchased from Amazon or Petsmart for about 140 to 145 dollars.
Critter Nation cage
Petco: Petco has its own rat cage. It is not too shabby. It has LOTS of levels, but they are wire and would need to be covered with wood or fleece so that they would not irritate the rat's feet. It is fine for two adult rats, or two or more juvenile rats, but anymore than two rats would need a bigger cage. This cage is priced at 75 dollars which isn't too bad.
Petco Rat Manor cage
I can't think of any other brands, but I would say that the BEST rat cages are the Prevue rat cage and the Critter Nation cage.