Can rats live in old dog crates? I'm getting a rat soon, and I can't exactly find a cheap cage. But I think I have a crate from when my dog was a puppy. It has wire bars and a plastic flooring that is removable. If I added some platforms and such, would it work? The rat is an almost full grown female albino rat.
I don't have rats but I'd be concerned if it could get through the wire since they can get through pretty small holes. How big are the squares? I know the crate I have, which sounds like yours, has fairly good sized squares. Also the plastic floor isn't attached so the rat could get under it & it would be quite the mess with rats bedding getting under it. Just my thoughts.
Quick google search:
"Another thing you need to look at is the bar spacing on the cages. With older males you can get away with a 1 inch bar spacing, but with younger males, babies and females, you will need to look at a smaller bar spacing, approximately 1/4 inch to 1/2 inch, depending on the size of the rat. Just remember, if the rat can get their head through, then their body will fit."
Can you post a picture of the dog crate? Chances are, it's no good, as rats need vertical space to climb in, as well as the aforementioned problems, and wire floors are awful for their feet, but you never know.
I wouldn't keep her/him in a dog crate long term. I do know someone who converted a large dog crate into a rat cage, but she has big males and they cannot get out. But still personally I would stick with a rat cage.
Rabbit, bird and ferret cages can be converted to rat cages pretty easily.