How do I keep my dog from barking so much during the day?

I have neighbors who work shift work and my dog barks continously during the day. I try to keep him in the house, but I like for him to be outside on nice days. What can I do to stop him from barking so much? He barks at squirrels, other dogs and sometime just barks for no reason that I can see.

Buy a kind of cap for the dog's mouth or u can make one out of paper cups(only if u can't buy them or find them) and just stuck it onto ur dog's mouth, not sure weather it hurts or not for the dog.

Buy citronella fragrance, and each time your dog barks spray the citronella over him.Citronella is harmless for both humans and dogs, although dogs doesn't like the smell.

keep him busy, buy him toys that make noises, or turn on the tv or the radio, that always works with my dog...

look its kinda your fault cuz when my dog was a puppy i stoped it from barking now it barely barks{and she is one of those yappy toy dogs}see you had to train it when it is small!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Try a muzzle.

Train your dog not to bark. When he barks, tell him "no" in a firm voice to show him it is wrong. Do this each time, he/she will be confused at first but stick with it! I don't really care for the electronic bark collars, I think they are cruel. And I don't think muzzles are right either. A neighbor of mine used the citronella spray and it worked ok, but the dog began to run away from when she saw the spray bottle. This just makes the dog afraid/uncomfortbale, does not teach it to stop barking. I did this with my dog when she was a puppy and now she never barks, not even at other dogs.