Crime deterrents come in many forms like cameras and security guards, but there's a surprising method that relies largely on psychology. Images of eyes staring back at you have been shown to make people behave better.
Posters with staring eyes have helped one UK police department reduce thefts by 40 per cent over a roughly seven-year period.
Similar efforts helped another UK law enforcement unit to deter shoplifting and a university to send bike thieves elsewhere.
The technique is called 'eye image compliance' which runs on the hypothesis that people become more aware of their behaviour when they feel they're being watched.
This works particularly well with humans because we have a brain system attuned to where the glances of others are directed, a function called gaze detection.
Researchers are unsure how long eye image compliance remains effective in any given space, and also if it's the stare that deters crime or just that it draws more attention to warning signs.
Bike thefts were slashed at Newcastle University simply by putting pictures of staring eyes above cycle racks, the Daily Mail reports.
The two-year experiment was carried out by a security manager at the campus who had seen similar studies suggest that people behave better when they feel they are being watched.
Academics found that bike racks which had eyes placed above them experienced 62 per cent fewer thefts than the previous year, while those without eyes saw thefts increase by 63 per cent.