Rats ate usally a verry good pet for everyone. But with kids and pets. Always keep watch. Dont let the children put fingers in the cage. Most rats dont bite but can do if they think you have food.
Here in sweden, we dont have so many dangerous disceases. Higher up in sweden there are found neprophatia/sork fever same as one string hantavirus. Came one rat from England with hantvirus. Think it was seola. No humans got sick. But more dangerous hanta string.
Can carrie salmonella and mycoplasma.
Last couple of years we also have had few cases of coccodios, bordetella, sda, cor and more cases with car, pastruella. And common with sda on sweden wild rats. But i dont think that is bad for humans. More bad for the pets.
But if getting bitten you should get tentanus shot.
Other wise. Rats are easie to learn. Social and loving pets. Wount live as long as rabits so more fun for parents ;).
Easie to keep and feed. Easie to take with you when traveling. But good to check countries rules befor bring over boundries.
Sorry some words i dont know the spelling and cant look them up now right now.