Although they generally try to avoid people, rats can become quite aggressive and dangerous if cornered, attacking out of fear. While many instances of rate bites are harmless, there is a chance the rat could infect a person with rat-bite fever. While rat-bite fever can be transmitted through a bite, as its name implies, a person can also become infected with this disease as a result of eating food or drinking water that has been contaminated by rats. If untreated, rat-bite fever can have serious, and potentially deadly consequences.