According to the cage calculator, the DCN should be able to house 12 adult rats, as long as you make good use of the space with extra hammocks and bridges and whatnot.
There are two homeless rats that are tugging at our heartstrings, but they look sick, so I'm not so sure that we'll adopt them, especially since one of them is so antisocial that she actually bit me when I tried to pick her up. But we have room for them if we ever decide to tackle something that difficult.
Personally I probably wouldn't put more then 8 rats in a DCN/ 4 in a CN. Cage calculators always say higher then what I personally agree with. Though I could see more working if u used space very creatively, gave them lots and lots of free range time and was very good at keeping it clean.
Well I don't have DCN but I do have Savic Suite Royal 95 which is almost the same and it's currently a house for two boys
They don't really use the lower part that much, but I like to offer them a big cage to live since I don't have a big free-ranging area.
I have a 1 dcn and 1 QC which is the same size (shaped different, not as much depth but much taller with 3 full floors and 3 balconies). The dcn has 7 girls in it and the QC has 8 boys. I could probably add a few more girls since they seem to always sleep in piles. The boys I don't think I'd want any more in, though they do sleep in piles there are times they seem to want their space and it would be difficult to make enough separate sleepy and hidey spots for any more than 8.
Six feels like a LOT more than four. D: I went from having four for a LONG time and now having six... It's a lot harder to make sure tiny hands, heads, and tails don't get crushed when doors are being closed and playtime out of the cage is nuts. XD I wouldn't trade it for anything, though. I love every one of my babies. <3 I'm really tempted to get two more, actually... But I shouldn't lol.
I have 1 Brazilian Short-tailed Opossum in 1 DCN. I had her in the top half for a year, then decided to open the bottom half for her as well. Now, she's used to having the whole cage and I have 2 recently adopted male rats, so I talked my husband into letting me set up our second DCN for them. So I will have 2 males in a DCN and 1 female STO in a DCN.
I've only got a single story critter nation and 4 of my girls live in it. I want to get a DCN but that would be twice the time to clean, I want more then 4 ratties but I'm going to stick with having 4 at a time.
I have my 2 older girls In a Double Critter Nation cage that's Mickey and Snowball they are around 8 months old and my 2 younger girls Summer and Breezy are in a Living World cage , it's the same size as the critter nation cage , they all have plenty of room
I have two very happy ratties in a DCN. They mostly stick to the top half. It has chewed up bits of paper and cardboard, they push carefresh out of the litter box, rip up the fleece as best they can.... then the bottom half is spotless, neat, and nearly untouched. I so want more rats....