There are a couple of explanations for why dogs howl at sirens, though not all dogs exhibit this behavior. Some think that a dog’s sensitive hearing is the direct cause and that they’re actually howling because they’re in pain. According to most experts, this is not the case and organizations like the American Kennel Club point to several other reasons why dogs howl at sirens instead.

Howling is not exclusive to dogs; it’s hard to forget the lonely cry of the wolf. Wolves and other pack animals do use howling, and although it sounds sad and lonely, it often serves another purpose. Because wolves and dogs both have very keen hearing, a howl can be heard from far away, and wolves use this as a form of communication and location. A howl can send up a signal that says “I’m here!” and the respondent howl of other wolves is a reply of “We’ve over here!”

When dogs howl at sirens, they may very well be expressing this instinctual behavior too. Some sirens sound like the faraway howl of a dog (at least to other dogs), and the dog may merely be being helpful by sending up a response. One howl often leads to another, which is why you may hear a whole neighborhood of dogs howling in response.

If you’ve ever seen the Disney classic cartoon 101 Dalmatians, the twilight bark that occurs between dogs over long distances is a good example of this pack behavior at work. When one dog starts to bark, others follow, which can lead to barking or howling dogs for miles and miles. It’s a communication device and seems a natural response for dogs to bark or howl to each other, and it seems to be largely instinctual.

What is interesting is that not all dogs howl at sirens, or only howl very occasionally when they hear one. For instance, noon sirens, which some towns or areas of towns may play, sound a lot like the howl of a dog. You may notice some dogs howl at sirens that sound most like other dogs, and ignore short staccato sirens that really don’t sound like howling. Other dogs seem to howl at all sirens and some pooches ignore them completely.

Dogs can be trained not to howl, mostly. Yet this wiseGEEK writer knew two collies that would run the length of an acre so they could politely howl at the noon siren each day without annoying their owner. If you happened upon them when they were howling, they did look very ashamed and would stop immediately. Some breeds appear to howl more than others, and sometimes it’s highly individualized.

You may find some dogs howl at sirens, other dogs, and a majority of the time. This may be a communication that says the dog is lonely. Since dogs are used to living in packs, the humans who own them are their pack. When a dog is not spending enough time with its human pack, it may bark or howl more frequently just to find other dogs. These howls aren’t inspired by noises like sirens, but may be a deliberate attempt to find other dogs so the dog doesn’t feel so alone.