|As I said, adorable whiskers!|
As it turns out, they do serve a function: whiskers supplement our sense of touch. They allow us to feel our surroundings when it's dark or otherwise difficult to see. They can also help us determine if we're able to fit into a particular space or not.
Because they serve a sensory role for us, you should be careful not to cut our whiskers if you're trimming our fur. However, if you accidentally cut them, you shouldn't worry too much because they will grow back. Similarly, some guinea pigs use barbering (gnawing on each other's fur) as a dominance-establishing behavior, and this sometimes includes biting off whiskers. If your guinea pigs are biting each others whiskers off, it might also be boredom, overcrowding, or a lack of fiber, so make sure they're getting enough quality hay and floor time, and have a big enough cage.
We have also read that blind guinea pigs can still get around fine using their whiskers and other senses. Therefore, if you happen to have a blind guinea pig, be especially careful with their whiskers!