I have seen many people who own cats whose houses smell 100x worse than a rat cage. You know the smell- uncleaned litter box! So nasty.
Also, rats being strictly indoor animals, are less likely to pick up parasites and diseases from outdoors like dogs or cats.
Now some rat beddings are worse than others in regards to smell, but anyone who cleans the cage regularly, and removes the poops as they are generated, should not have any health issues.
If you are going to have some kind of inspection, where DCFS needs to check the house to make sure it is suitable for kids or whatever, just get some white carefresh and clean the cage and replace the bedding right before the visit. Not that a day-old cage is any less healthy, but a pristine layer of bedding just looks nicer.
If anything, I would worry about the kids hurting the rats, not the other way around. Kids are monsters.