For almost as long as humans have existed we've understood the importance of home security. From the caves and clubs of the Stone Age to the moats and castles of the Middle Ages, ensuring our homes remain secure and private has always been a priority.
While most security systems today are pretty run-of-the-mill, some are more exceptional. Ranging from obscenely expensive high-tech gadgets to surprisingly simple inventions, we've compiled a list of some of the most original and inventive security devices around - but are all of them effective?
1. The Robot Security Guard
Human security guards are all very well and good - but they are also fallible. With robot security guards however, human failings don't come into it; no sickness, no daydreaming, no pay demands, no secret cigarette breaks on the job. Created by tech company Knightscope in 2013, these five-foot-tall, 300-pound sleek white robots - named the K5 - look like something straight out of Star Wars. Designed to detect anomalous activity, the aim is to have these robots acting as security guards in the not-too-distant future.
2. Mind-Controlled Robot Spy Dog
We all know how effective dogs can be when it comes to guarding property - but how does a robot spy dog fare? Though it may sound like something from a bad science fiction novel, robot spy dogs are actually already available to buy in many stores at the startlingly low price of $170. These robots are the size of a small dog but unlike man's best friend, they are equipped with a camera, microphone and speakers and can show the owner exactly what's in front of them.
3. Mosquito MK4 Alarm
Not all innovative security devices rely on sophisticated technology, as the simple yet effective Mosquito MK4 alarm proves. Created to tackle anti-social behavior, the MK4 is marketed as a security device that prevents young troublemakers gathering outside other people's property. The alarm emits a grating high frequency sound similar to that of a mosquito - but only audible to those under the age of 25.
Created by former aerospace engineer Howard Stapleton after his daughter was threatened by a gang of youths loitering outside a store, the device has sparked controversy due to its purported discriminatory stance. Stapleton has defended his device against these claims: "Many home owners and families have antisocial-behavior complaints but are not getting the assistance they deserve. If nobody is going to help you, you have to help yourself."
4. The Smoke Cloak Fog Alarm
If despite your best efforts intruders gain access to your property, you need to get them out - and fast. One sure-fire way to make burglars flee in a panic is to spout a mysterious gas at them. While the intruders won't know that the gas is actually a harmless fog, they also won't be able to see - which means they won't be able to steal. That's not all the SmokeCloak fog alarm does, however; the fog is actually coded with unique botanical smart DNA which links any intruders to the scene of the crime and ensures law enforcement are able to correctly identify and convict those responsible.
6. Response FakeTV
While a burglary occurs every 14.6 seconds in the USA, it's a given that nobody wants to burglarize an occupied house - but if you're on vacation or out of town, how can you ensure that your absence isn't picked up on by potential thieves? FakeTV could be the answer - another surprisingly simple device.
This small gadget automatically comes on when dusk falls, emitting precisely the same sort of light as a real TV and simulating the effects of changes in on-screen color and motion. Using a fraction of the energy it would require to leave your actual television on while you're away, FakeTV uses even less power than a night light.
So, for all their high-tech futuristic functions, how effective actually are these security devices? Jay Robertson of Protection 1, the US's largest comprehensive security firm, urges consumers to be wary of security devices that are actually more of a novelty.
"The more modest devices like FakeTV can be helpful in deterring potential burglars, but if they do gain access to your property it won't stop them taking your TV, real or otherwise. It's limited in its efficiency; the same applies for the SmokeCloak. Unless you have it installed in every room in your house, an intruder can just move into a different area. Tracking their DNA can be useful - but only if their DNA is already on the system."
While it may be a few years yet before we can expect to see robot security guards gliding around in our schools or malls, technology is advancing at such a rate that we can say with confidence it will be sooner rather than later; just how successful these devices turn out to be when put into practise, only time will tell.