Each year hundreds of homes in our area are broken into. You might be surprised to hear what burglars say is most likely to scare them off -- a dog. Most pets are not trained to respond to an intruder. Channel 3's Tim Pham put a local pack of pups to the test to see if their bite is as big as their bark.

"He will go check it out and start barking if it's creating noise," said Stephanie McGuffie, Cooper’s Dog Owner.

Three local families let us put their pets to the test, our crew set up several cameras to capture every angle. We asked Scott Taylor, a professional dog trainer with ‘Off Leash K9 Training’ to suit up to play our intruder. He trains dogs specifically for home protection.

“To give them that kind of security is kind of like a first line of defense for the home,” Taylor said.

Cooper is up first, a two and half-year-old Australian Labradoodle. McGuffie is confident she knows how Cooper will react.

"At first I think he's going to bark and hen he's going to smell the person and probably start licking him,” McGuffie said.

Scott jiggles the doorknob, Cooper goes to the window but doesn't bark and he wasn't fazed by our crew either. Our intruder easily gets away with an iPad.

"I definitely thought he was going to bark when he saw an unknown person so that was a little unexpected,” McGuffie said.

Taylor said Cooper's response is more common than you might think.

"You have a dog that's great with people and that's what you wanted is them to be great with people that's going to be the exact reaction,” he explained.

Next up is Winston, same breed as Cooper, but his reaction was different. His owner, Shannon Bielcik said he's good about alerting her.

"He will bark, I think and then I think he'll get scared and run away,” Bielcik said. Scott peered through the window, no sign of Winston, but that changed when he heard Taylor at the door.

When Taylor makes it inside, Winston continues to let him know he's not welcome.

"He saw I wasn't going away so he backed off he never approached me he kept barking, it wasn't a playful bark, it was a bark like hey this isn't right you shouldn't be here,” he described.

Winston didn't stop barking even after Shannon returned. 

"He is still very worked up right now and I’ve never seen me not able to calm him quickly,” Bielcik explained.

Despite the barking, Taylor was still able to nab valuables without any physical aggression. He said most pets are protective of their owner but need the training to respond aggressively.

"The odds of that dog doing it naturally are astronomical,” he added.

Drachen has worked on his skills for about a year, he’s a trained Doberman protection dog.

His response was different when we sent in our intruder for our final test. Taylor doesn't get away with anything, however, Drachen bites, and lets out one more bark to let him know it's time to go.

"They see that the dog means business, whether it means business or not it has the perception of meaning business and sometimes perception is reality,” Taylor said.

He says no matter the size or breed, a dog's bark can be enough. Burglars list a barking dog as one of the top five reasons they won't break in. 

"Maybe all bark and no bite,” Bielcik said.

Without proper training, dogs can become defensive biters. Trainers say every dog is different and it takes a unique approach to learning safe protection behaviors.