Hi Meghan,
I have owned those Superpet cages you mention. They are great cages for
older rats. Males can go in at 3 months and females at around 5 to 6 months.
Any younger and they will escape through the bars.
I have just sold all my Superpet cages and have switched over to Martin's
cages. The reason being, I prefer the ladders to be wire instead of the
ramps from Superpet. The wire ones, the rats have a way better grip and it's
not as steep.
I cut up rubber mats to fit all the levels. Like you, I can just image that
the wires must hurt. But really, what do I know, I'm not a rat. Have you
taken a look at rattie feet lately? They have like tiny bumps, and they sure
look like they were meant for walking on wires with no problems.
Wire flooring is no longer the real cause of bumblefoot. As discussed with
my vet, bumblefoot is usually the occurrence of being overweight and being
elderly. Also, bumblefoot will occur due to the feet constantly being
pressured down on levels. And think about it, on wires, their feet don't
always sit flat on a hard surface. Bumblefoot is almost exactly like bed
sores in humans. It's a pressure point. But then bacteria sets in and not
treated can go right to the bone and this is very dangerous for the rat.
Unfortunately bumblefoot is very hard to treat. The ideal situation would be
to no longer have flat hard surfaces for rattie to walk on so no pressure on
feet: sponge the whole cage? Impossible... but you can make things not so
hard with lots of bedding, TONS of shredded newspaper would be ideal as the
urine dries real fast on paper as opposed to towels.
Ok, back to cages... sorry, rambled off there...lol
The bigger the better... trust me, if you love rats now, you will get the
addiction: GGMR: gotta get more rats.

And so you can add more. BUT:
ideally, your rats will benefit from a huge cage. This gives them a good
habitat, with plenty of territories for them to call their own. This reduces
fighting, scuffles, hormonal surges and stress. Above all else, you want to
avoid stress in your rats. This can cause so much more: myco, weakened
immune system, secondary infections, porphyrin... etc...
Add lots of stimulation in the cage: ropes, balls, paper towels, hammocks,
ladders, bells, boxes... let your imagination go crazy.

I hope this helps...
--
Joanne
Mom to 12 rats
http://community.webshots.com/user/joanneb70