Cage

Question
So I've had my rat Baley since the summer, when he was a
baby. His cage (12"x24") was big enough for him then, but
now he's seeming a little too large for the cage. I'm
planning on getting some wire mesh to extend the height of
the cage, and I was wondering what kind of wire is safest
for rats? Is stainless steel safe?

Answer
If you have the cage I think you have, (its a single story, white?) A while back before I invested in a ferret nation, I bought two more cages just like the 12 X 24, cut a hole in the ceiling of the first cage, removed the base of the new cage and just put the cage part on top of the TOP of the cage below, fastened all of it with zip ties and laid down white needlepoint canvas to make the floor solid. I ended up making a three story cage this way. I ended up with two metal bases that went to waste but had a nice three story cage for two happy males!  I did have old ladders from an old cage to make it easy to get up to the next levels but you can buy a wooden bird ladder from a pet store or perhaps look on the internet for cage accessories.   Stainless steel is too porous and will absorb urine odor and smell hideous after a few months. You would need to get your hands on galvanized steel which would be a real pain to work with. It would be better to add on to the cage building up like I suggested.