If a dog is barking, it’s not at nothing. Ever.
Sometimes, my dog will wake me up at 3AM from barking.
I’ll see him sitting on his bed, staring at nothing.
I used to tell him to be quiet.
Then, I realized one night that he had been barking at a stray dog that kept coming back.
If that stray dog was actually a human thief or predator, then I would never had known had my dog not barked.
Dogs are not just pets. They are your aid. As annoying as their barks can be, they are infinitely more useful.