As some people experienced in 2009, the worst bushfires can kill indiscriminately, ruin people's homes and livelihoods and severely tramautise communities for years afterwards.

A devastating bushfire is the last thing most people want to see.

And yet, statistics reveal an astounding number of Australian bushfires are likely caused by arson.

The Australian Government Attorney-General's Department Bushfire Arson Prevention website states that Australian authorities respond to more than 19,000 "suspicious" bushfires each summer.

The central Victorian community has not been immune to the effects of bushfires, with the Black Saturday bushfires in the Bendigo region - which police thought were suspicious - killing one man and destroying 61 houses.

Bushfire arson stings our emotions and makes tempers flair, but the question remains: why do people do it?

Clinical and forensic psychologist Troy McEwan says the reasons people start fires are not as malicious as one might initially conclude.

She says while there's no typical profile of an arsonist, studies have shown many firesetters have debilitating emotional issues and use fire as a way of expressing themselves.

"I work with clients who have low intellectual functioning and they use fire when they are feeling down," she says.

"The fire is exciting and interesting and it gives them pleasure to set a fire."

She says offenders are typically enthralled with fire from a young age, and learn that playing with fire can garner positive effects, such as getting them attention.

“What we see in firesetters more generally is they tend to lack communication skills, the ability to control their emotions and fire becomes a way of overcoming those deficits," she says.

"People use fire to express emotional distress because it's a very attention-grabbing behaviour.

"You light a fire and people attend to you."

Ms McEwan says there are also significant cases of young men starting fires together, as a form of acting out.

"In those cases, it's mostly to do with boredom," she says.

"They probably do other things that are socially unacceptable. It's exciting and a bit dangerous."

She says offending peaks before the age of 25, and Bendigo Police Senior Sergeant Craig Gaffee recently told the Bendigo Advertiser a significant amount of offenders in the Bendigo region were children and teenagers.

However, while it appears juvenile delinquency accounts for a significant number of bushfire arson cases, Ms McEwan is quick to point out that arson is a difficult crime to investigate, and it could simply be that young people are more likely to be caught for the crime.

Indeed, the Attorney-General Department's Bushfire Arson Prevention website states that it is estimated less than one per cent of bushfire arsonists are caught and convicted.

Bendigo Police Senior Sergeant Bruce Simpson has said previously that solving arson cases is challenging.

"Quite often there's a lack of witnesses and evidence is burnt so that makes it difficult but not impossible," he said.

"Every (suspect) is investigated as thoroughly as they possibly can be - any trends or links are fully investigated."

Victorian Police Arson and Explosives Squad Inspector Mick Roberts says arson can be difficult to investigate due to its "random and unpredictable" nature and the fact fires are often in remote locations.

He says people start fires for a number of reasons, including gain, revenge, sexual gratification and power.

"Often arsonists are emotionally triggered prior to starting fires," he says.

Ms McEwan says to better solve arson cases there needs to be more research into arson behaviour. But she does debunk some popular theories about bushfire arson.

She says while Sigmund Freud theorised that firesetting stemmed from perverse sexual desires and "everyone always talks about firefighters who start fires", Ms McEwan says neither of these phenomena are common.

Of Freud's theory, Ms McEwan says while some arsonists might have multiple anti-social behaviours, including perverse sexual behaviour, there's no solid evidence to suggest arson and sexual arousal are inextricably linked.

As for emergency service personnel who start fires, Ms McEwan says these perpetrators believe they can control the fire, and start one as a means of demonstrating their skills.

"It's a way of showing control and mastery," she says. "It has an element of grandiosity, of 'look how good I am'."

Indeed, a 2003 study, Special report: Firefighter Arson conducted by the US Department of Homeland Security states that starting fires provides some firefighters with "a feeling of empowerment over society."

It says firefighters "are known to set fires so they can engage in the suppression effort".

"Firefighter arsonists who seek recognition, or wish to be viewed as heroes, may set and 'discover' the fires"," it says.

However, Ms McEwan stresses that a tiny percentage of fires are found to be started by firefighters.

She says most of the bushfire arsonists she has encountered have mental health problems and don't set out to cause significant damage.

“Usually it’s not intending to do all the damage we see," she says.

“Usually they don’t think through the entire consequences of those actions.”

Emergency Service Commissioner Craig Lapsley echoes Ms McEwan's sentiments.

"An arsonist, in my opinion, has a mental health problem and needs support," he says.

He says there are services available - such as a program for young offenders run by the CFA - to help people prone to starting fires, and relatives should seek help for their children if they are concerned. 

"I say, people will know an arsonist," he says. 

"People who are arsonists play with fire and they've probably played with fire all their lives.

"I'm sure people know who they are and there are programs to reach out and help."

Victoria Police Acting Deputy Commissioner Jack Blayney also recently said people who commit bushfire arson are "not always strangers" and often "live and work in local communities".

In terms of what people can do to prevent people from starting fires, Ms McEwan says the media has a role to play in resisting the temptation to glorify fires, which can send out the wrong message that fire is exciting.

She also says parents should teach their children about fire in a calm and rational manner. 

"Make it a normal thing - not dangerous but not forbidden," she says.

"Be calm around fire so it doesn't get these emotional connotations where kids use it because it's dangerous."

Senior Sergeant Gaffee says parents need to educate their children about the danger of fire and the potential consequences of starting one.

Of course, the police also have their part to play, and in the past few weeks the Bendigo community has heard of their vigilant efforts to prevent bushfire arson.

Police have recently relaunched Operation Firesetter - monitoring known firebugs and patrolling forested areas - and will conduct "rigorous investigations" into suspected cases of bushfire arson.

With this year's fire season already off to an active start, Acting Deputy Commissioner Blayney said police would try to prosecute as many cases of bushfire arson as possible, to prevent further devastation.