When people ask us to take in rats there is always a reason. I'm moving, I'm allergic, I have seen them in a bad situation, I have rescued them from a bad situation, and so on. Usually they include a sense of urgency and occasionally are a bit threatening. ie. If you don't take them I'm going to dump them in the river or some such. Depending on who you ask many of these reasons, and often threats, are complete hogwash, or partial hogwash at least. Sometimes you catch them on it and sometimes you simply don't believe them. Either way we take the animals if we can, we are a rescue after all.
This was the case with my last two rat fosters. In the request we were told that they were originally from a pet store where they were kept alone in fish tanks. Not the best type of cage as they are small and tend not to have proper air circulation but not animal abuse. The person who was surrendering them said that her friend had rescued them from the pet store but couldn't care for them so was leaving it to her to find a home for them. This person has many other animals so couldn't keep them. When they arrived at my home the story changed slightly to be that she had rescued them from a bad situation but couldn't keep them due to her own menagerie. Slightly different, a few less details, but ok.
When the girls arrived they were so friendly. Being inquisitive, letting me handle them, running all over me and taking treats by hand. All signs of a well cared for and handled rats. They were in good health, but did have a little bit of a cold. Colds just happen. Very not typical for rats in a "bad situation"
I only had the girls for Quarantine aka 3 weeks. They were lovely girls who amused me by being hoarders. This means you can feed them block by block and they will take it to their food hiding place and then come back for more. Piece by piece, once for over 20 minutes. It's hilarious. Their names are Audrey Lorde and Syliva Rivera respectively.