WHY? where do u get it from in australia??

I would say a critter nation or one of martins cages. You can order these from their websites. I'm not sure about Australia but normally in pet stores the "rat cages" are normally way too small and hard to clean. The cage you choose should have two square feet per rat and should be well ventilated (no aquariums) . Hope this helps

I don't know what cages you can get in australia so just look for a wire cage with 1/2 inch bar spacing for females and babies and 1 inch spacing is fine for adult males and a solid floor. It needs to be at least 2ft by1.5ft by1.5ft tall. That's the minimum for 2 rats. If you have more than you will need a bigger cage.

Definitely not a cage with very large spaces between the bars, because rats can escape easily if the bars are not spaced right. I'm not sure about where in Australia though...sorry!