corus My girls do that more than my boys do strangely, but one of my boys always does it on my trousers in the crotch region. Every single time he is out
Urine marking isn't too obvious though, it's minimal, literally drops of wee rather than puddles of it. We tend to use the same three jumpers and have found that they don't mark them as much, probably because they recognise the smell of it, which is why I think that Howl marks my trousers, because I change them daily but not the jumper.
Female rats have a 62% chance of getting mammory tumours according to some studies. You can get them spayed young to dramatically cut that risk. We would spay any baby females we got in future unless we were breeding, but it's a very personal decision and one that you should talk over with your vet to make your own decision on it. For us it would have the benefit of having the mischeif all in one cage, which we're keen on. Having two cages is a pita at the moment!
Boys don't smell too bad, the cage gets stinky by the end of the week but it's not awful. Our boys have quite a musky smell to them and can get a bit smellier poos when eating fresh carrot, not sure why by we couldn't work it out until I found a tip online about carrot!
Their tails are lovely, our boys stick theirs out of the cage and we'll sit playing with them for ages.
RE cages, I'd recommend looking at metal base ones for girls, they're generally bigger and a bit more expensive but it stops the little sods chewing through the cage
Our girls have chewed holes through two plastic bases! They didn't go any where though
We noticed two holes in the corners next to the wall, patched them up with baking trays and cardboard for the night (at stupid-o-clock in the evening), went to bed and woke up in the morning to a brand new ratty sized hole in a third corner. Put them in their old cage and they put another hole in it within a day.
Haha, our boys sleep with their balls hanging out between the bars of the cage, it's hilarious!
You also need to look at cages with narrow bar spacing, less than 2cm. Girls can get out of anything bigger. A smaller cage will do for now but I wouldn't leave it too long before replacing it. Keep the old cage as well though, smeller cages are handy for travelling with them for a few days or so.