Pro: Rodents are just awful and giving them diseases is a very fulfilling career.
Con: Paperwork is just awful and is required to give rodents diseases.
Pro: You can be on that list of people the government saves from the Apocalypse.
Con: Chances are everyone else on the list sucks.
Pro: Surgery is the only way you can legally stab people.
Con: Strict "no snacks" policy in operating rooms.
Pro: Giant ants don't just create themselves, so you can make some.
Con: Giant ants will probably create themselves once you get them started.
Pro: You may be the one to cure cancer!
Con: You won't be.