“It’s going to look for the deer – it’s going to attack the frail animal that’s not going to put up too much of a fight,” he tells them. 

"Often bullies are very similar. But when you learn martial arts you walk straighter. Your confidence is up, you're less of a target." 

Earlier this week Mr Cooley was horrified by footage showing a 13-year-old boy being savagely bitten on the face by a man who allegedly wanted to rob him of his shoes at a crowded Macquarie Park shopping centre. 

In response, he is now encouraging area teens to attend free martial arts lessons at his FiveStar Martial Arts School during the school holidays, to learn how to defend themselves. 

“I have lots of kids here that are that age [of the victim] and the footage does strike a chord,” he said.  

"The fact that someone's so brazen to come up to somebody in a mall. 

"I was horrified, as were many of my martial arts colleagues.” 

Having watched the footage many times, Mr Cooley believed the bite victim, Decklan Manley, could have taken steps to protect himself.

By the time the bigger, stronger, biter clamped down on his face, he had nowhere to move, he said. 

Read more: Illawarra man’s face sprayed with blood-filled syringe: court

“By the time the guy bit him I think he was in shock and didn’t know how to react. His face was like, ‘man, if I move he’s going to rip my face off’. 

“The breakdown of that situation happens before that. 

“It happens before the guy starts talking to you and as soon as he starts to make that challenge.

“When you’re met with that challenge you’ve got to nip it in the bud straight away. It might be seeing an undesirable person come towards you and walking away. 

He is inviting interested teens to drop in to his lessons, which run five days a week, in line with a schedule on the school’s Facebook page. 

“I’m not going to teach them to do spinning kicks or Olympic kicks – that takes a long time – but I can teach them ways to hold themselves, and things to look for, and simple escape mechanisms.” 

The attack at Macquarie Park was allegedly over a pair of Nike TNs, which retail for $280. 

The victim has since told news.com.au that the shoes were knock-offs, purchased in Thailand two weeks earlier for $25.