Rodents and rats typically denote a negative connotation. They're dirty, disease-carrying creatures, ready and willing to resurrect the black plague, crawl up your pant leg, and "rat" you out to the cops -- not exactly the Internet's favorite animal.
But like most dangerous animals, rodents can be also incredibly cute, and sometimes they can make great pets too.
[seealso slug="animal-olympics"]
Which do you prefer: cat or rat?