Why Dogs Bark and Bite Some People (And Not Others) – What’s Really Going On
November 3, 2025
source: Pixabay
Do you ever pass by a dog and it completely loses it on you? Barking, teeth, chaos, then two seconds later it’s wagging its tail at the next person like nothing happened? And you’re sitting there trying to figure out, “What’d I do?”
It seems completely random, but it’s not. Dogs almost never act randomly. There is always a reason — a scent, a noise, a movement, a feeling. You just don’t always get to see the numbers.
I’ve spent a long time thinking about this — why some dogs bark or bite at some people but completely ignore others. It’s not one thing; it’s a mix of instincts, history, energy, and sometimes your deodorant.
Let’s take it apart.
Always Fear Comes First
The number one reason dogs bark or bite? Fear. Most of the time. It just doesn’t look like fear; it looks like confidence (puffed-up) or a full-on lunge. But under it all, it’s still: too much, too fast, I don’t like this.
Some of the reasons can be extremely small. A quick movement. Large gestures. A jogger running right at you. Even your posture. Staying upright and making direct eye contact with a strange dog? That’s not friendly in dog language — that’s aggressive.
Also, here’s a pro tip: don’t lean over a dog you just met, even if it’s wagging its tail. That is a large move and will look threatening. Think of it this way: if someone huge was leaning over you uninvited, you would jump away also.
Scent: The Stuff You Don’t Think About
But weirdly, and very similarly big fact: scent. What you smell like could possibly make perfect sense to you — but not to the dog. A dog’s sense of smell is tens of thousands of times better than ours. Everything is based on scent to them.
If you’ve been around other animals, used perfume, smoked, or even just washed your clothes recently using a new laundry detergent, they’ll notice. Walk into a room smelling like the vet’s office? Done. To them, you smell like trauma.
When a dog barks at you, it may not be you at all — it’s what you smell like. Maybe your clothing smells funny or the laundry detergent does. Whatever it is, it said to the dog, “you’re not okay,” “you’re not a familiar scent.” And the dog reacts first, figures it out second.
Energy Is a Thing, Sadly
You ever meet someone who you immediately feel uneasy around even though they’re being super nice? Dogs do that too — but ten times worse. Dogs watch for posture, tone, speed, energy. When you enter a room looking jittery, loudly, or stiff, they pick that up right away.
Two people can walk up to the same dog: one quietly, calmly, one bouncy and loud. One gets a tail wag; the other gets barked at. This isn’t about whether you’re a “dog person” or not — it’s about understanding when to turn yourself down.
Walk slower. Talk quieter. Never run past dogs — they can’t tell if you’re prey or a threat, and their brain goes directly to either run-after or defend-yourself mode before they even think about which.
History Can Leave Some Serious Emotional Scars
Sometimes it has nothing to do with you — it has to do with their history. A dog may react to something that reminds them of a previous traumatic event, such as a tone of voice, a jacket, even a body type. Especially with rescue dogs.
If a dog has been abused or didn’t receive proper socialization, everything feels like a risk. You’re just walking by, they’re reliving something that scared them.
Dogs that were socialized correctly from the start generally deal with new people better. For the rest, you need to give them time to slowly create new safe experiences. Trust cannot be rushed.
Built-in Instinctual Stuff
And sometimes it’s not emotional at all — it’s pure instinct. You’re in my area. Dogs naturally protect their territory — home, family, car window, food dish.
This is why they bark at people from behind a fence or when a stranger gets too close to their owner. Protect the pack. Protect the den.
While you can train extreme reactions out of a dog, this instinct is never going to go away entirely. Knowing that gives you the power to react instead of overreacting.
Okay, Now… What Can You Do?
Now that we understand how dogs work…
If you don’t want to be the person that sets a dog off — slow down. Your pace, your voice, your hand movements. Allow the dog to come to you. Don’t try to pet it or stare at it. Just stand back, allow it to sniff you, and wait.
With children, teach them to behave calmly — no screaming, grabbing, or running towards the dog. Children are usually unaware of how quickly things can escalate.
If a dog shows warning signs — ears laid back, growling, frozen — step back. Don’t “show dominance.” That is old-fashioned nonsense that puts people in danger of getting bit. Fear can’t be beaten out — it can only be suppressed and eventually erupt.
If it is your dog that reacts this way, seek the help of a professional. A good trainer who uses positive reinforcement techniques can help to fix behaviors without scaring your dog further.
Punishing behavior only creates fear, not confidence.