LOL - it's only when they do several pisses on top of each other it starts to smell
But to be fair, even my incontinent old fellas (the ones who couldn't help it due to spinal degeneration) didn't smell - because you keep on top of it, change their bedding when it needs it, rather than sticking to the guidelines. Hint for unsmelly rats - clean 'em when they need cleaning. If that's once a fortnight (yes, I know folks who are just that lucky!), every week, or twice a week, or changing their hammock every other day because they're bedwetters - do it. Because if you can smell it, think of how much they can!
But honestly, mine dont smell bad - unless I've had something on and not been able to clean them out on time - but that wouldn't be them smelling bad - it would be my fault. Generally, if your rats smell bad - it's not because they're dirty rats, it's because you're a lazy owner. And I dont mean anyone in particular here, I mean "you" like the Queen says "one".
Rats are very clean animals, that's why they spend most of their day cleaning themselves (well, apart from the late Fred, who spent most of the day eating, and therefore less time washing, and made sure I had to bath him instead lol), and prefer company - so they have someone else to help them. And because they all carry myco (respiratory disease found in all rats apart from lab rats), if they get stinky you can be risking their health.
I'm saying all this, and I was supposed to clean mine out tonight...