I think every animal comes with it's own little stereotype, whether or not it is true. Cats smother babies, all dogs will at one point turn on you, sharks always kill people, spiders will bite you, bears will attack you and snakes will poison you.
The thing is, a lot of the time it's true. If your child has an allergy you're not aware of, your cat may well smother it. If your dog is badly brought up, abused in a former home, sickly, etc, it may turn on you. If you swim next to a shark in the ocean, you may easily become food. If you surprise a spider, it may bite you, if you startle a bear, it may attack you, if you threaten a snake, it may bite and poison you.
The problem with rats is that so many prejudices have followed it throughout time. Rats were a major carrier of the plague in the past because of the fleas they carried. Why rats? Because there are more rats than there are dogs, cats, and people.
Wild rats are also something to rightfully be careful of. When attacking, rats (like many animals) will instinctively go for the jugular vein. They know how to kill you. They, like all wild animals, also carry an array of parasites and diseases.
If I were to see a roof rat in my home, I'm not sure I wouldn't kill it. It's tough, but rodents invade quickly and cause a lot of damage. When I was 12 years old I was kicked out of my foster home for insulting my foster father and shoving him after I had complained about the cruel way he disposed of mice that were caught in the house. I still hate him for the way he treated animals, and I still think he is sick. But now that I am living on my own I have been through what it is to deal with rodent infestations. They wreak havoc. You would not believe the damage that they can do unless you have had the problem. I have tunnels running throughout my entire apartment with multiple holes to each room. I come out in the morning and mice jump out of my garbage can and run under my stove. Traps don't even work any more, they're too smart for them.
Imagine a rat infestation. Like mice, only bigger and smarter.
They don't just wander around, either. They get into your clothes, your bed, everything. I had a friend tell me yesterday about a friend of his living in Toronto who actually leaves out food so the rats will stay away from him in the night. We all own rats here. It is foolish to think that a rat that wanders around on your floor can't get into your bed. I've shaken mice droppings out of my sheets. Mice and rats don't creep me out, so I don't really care, it doesn't get to me. All the same, mice are up there on my list of reasons for moving out of this house.
As a final note, as a rat owner, if you see wild rats in your house, I can not believe that you would not want it gone as quickly as possible. The mice in my house actually steal food from my rats. The bar spacing on the cage is such that they can squeeze through and get at the food. They used to scale the stand and steal food from my love birds as well. If your food dish is anywhere near the edge of the cage, I can see wild rats being clever enough to fish it out, and I can see my fancy rats getting parasites from wild ones.
I have to say, if I saw a wild rat in my home I'd be setting traps.
