Hi J., (YES TO THE PET RATS)
We had a pet rat when my son was about 9 or 10. He really wanted one for a long time and his schoolmate had a mom rat with a new litter. They start out very small. My son picked his rat out and we named him Ben. (It was a big name back then because of Michael Jackson). Ben grew to be a very big, gray boy with a long rat-tail. He pretty much grossed my family out when they would visit, but my son Paul loved him and I actually grew to love that rat as well.
Ben lived longer then most rats, but that probably had something to do with the money I spent at the vet, (yes rats are seen at the vet) and the vaporizer I bought him when he got a cold. PS.the vaporizer ruined my bathroom paint job, but it was OK, because Ben was a great pet and we were sad when he went to rat heaven.
As long as your child keeps the cage clean and makes sure there is fresh water and food (daily), a rat can be a good pet. Not dirty like most people may think. The pet store has special wood chips for the cage, but if you can’t afford it, shredded newspaper works just as well and they like to play in it.