Just like any other animal. Dogs use their whiskers for sensory reasons. There really isn’t much use for them for anything else, but for what they do, they are indispensable.
If you didn’t know, dogs do not have shoulders. Their body is roughly the same width no matter where you go. So to a dog, there’s no real way to tell if they’re going to fit somewhere or not. It’s really easy to go into something but much more difficult to get out especially if you’re wedge shaped to begin with. When a dog sees a hole that they may or may not be able to go into, they’ll usually enter it head first very slowly. Their whiskers are a little bit longer than their head so that they come out just past their jowls. If their whiskers do not touch the outside of the hole then they dog will readily walk in, if they do, he or she may be a bit more hesitant.
Also the whiskers themselves are very sensitive like strings on a violin. Some vibrations can be picked up on them, sort of like a sixth sense, and dogs may be able to predict something is going to happen in the near future like a tornado that humans could not pick up.
Some believe that the dogs can pick up radio signals with their whiskers but this is up for discussion. Scientists do believe that certain waves can be picked up on the whiskers which is why dogs are so good at knowing when something bad has happened or will happen.
So the next time your dog starts freaking out for absolutely no reason, you might just want to keep your head down a little bit lest a tornado comes through your house.