Rats can't vomit. A rat can, however, gag on something if it eats too quickly. The plus side of this is that rats can usually eat and drink before surgery. You can't catch rabies from a rat. Soda does not make rats explode.
Rats bathe themselves, usually six times a day or more.
A rat's saliva has some pink pigmentation, which can cause a light-colored rat to look discolored. A warm washcloth with baby shampoo is great for those trouble spots. Rats have bellybuttons. Rats don't have gallbladders. Rats don't have tonsils.