Earlier this week I realized something about Muppets from Space that I don't think has been brought up before: The scientist played by David Arquette in Muppets from Space gets away with his mistreatment of Rizzo and the other rats.
Also, he's a jerk to them, and later on, when they save Gonzo, they attack Dr. Phil van Neuter, who reveals to hate rats, presumably because he's scared. I wonder if there was ever any consideration for both characters to be the same. It would make sense - this scientist who takes pleasure in making the rats take tests and bullies them, who ends up getting attacked by them. His line about hating rats could have been reworded to something like "I hate rats outside of cages". The attack would have been out of revenge as much as it would be to help Rizzo rescue Gonzo. Of course with Dr. van Neuter hating rats it makes sense he would not be too keen on conducting the tests. Then again, he could have been an assistant to the other scientist, acting a little scared of the rats while also mocking them a little.
It's also interesting how in Muppets from Space, we have rats, who speak English and act human, be made lab rats against their will, and later on, K. Edgar Singer gets Bobo to reveal something he knows by threatening to send him to the petting zoo or circus. And this is not only a bear who talks and acts human, but is also an employee.