Pet friendly alarm systems: do they work?


Investing in high-tech home security is probably the wisest decision you’ll ever make. Burglary rates continue to rise, so you need all the protection you can get. But, what about homes with resident pets? Can you still use alarm systems in these households without triggering false alarms? Well, the answer depends on the type of alarm system you’re using and where you’ve placed the motion sensors.

If you’ve placed the motion sensors in the right strategic positions and bought a pet-friendly home alarm system, then there’s absolutely no reason why you shouldn’t be able to protect your property. The best advice, however, is to do your research before you part with your cash. There’s no point spending a small fortune on home security, if you’re having to constantly apologise to angry neighbours and the police because of false alarms at your property.

Why are false alarms so problematic?

False alarms can be a real problem. They waste valuable police time and resources, and can alienate neighbours. Nobody wants to be woken up in the middle of the night, or be called out to an attempted burglary at the best of times. But if the emergency call-out proves to be unnecessary, or turns out to be a false alarm triggered by pets doing what pets do in the middle of the night, then people are quite rightly going to feel aggrieved. The problem will be compounded if these false alarms happen regularly. The police and neighbours will quickly develop ‘alarm-fatigue syndrome’ and that can be a serious problem on the one occasion your home is actually being burgled. 

Pet-friendly motion detectors: do they work, and which one is the right choice for your home?

Standard alarm motion detectors will detect all motion within a property – both human and animal. So their use in domestic settings is limited, as they won’t be able to distinguish between a burglar’s movements and a family pet’s. Pet-friendly motion detectors, on the other hand, can usually spot the difference: or so they claim.

Pet-immune motion detectors have been developed by engineers and programmers. After exhaustively studying the behaviour of pets, and recording the movements of both humans and animals, researchers converted this information into sophisticated algorithms which are able to distinguish between human and animal movement. The algorithms use a combination of different technologies to determine, amongst other things, the mass, speed, and movement patterns of any moving object and the body temperatures of these moving objects, in order to detect infrared emissions. They should, therefore, be able to rule out household pets.

Active and passive motion sensors

There are effectively two main types of motion detectors:  active and passives.  Active motion sensors emit energy waves that detect movement, whilst actively searching their field of view. Passive systems don’t emit energy waves: they simply look for changes – like body heat in the area the sensor is detecting.

Which type of sensor is best for your home? Well, that depends on which areas you want the motion sensors to cover, and how you ultimately plan to use the system. The type of motion sensors most commonly used for home security purposes are passive infrared (PIR) and active infrared (IR) detectors.

Differences between PIR and IR motion sensors

Passive Infrared Detectors PIR sensors look for changes in heat and movement in the sensor’s coverage area. When someone, or something, moves across the sensor’s field of view, the sensor detects that objects’ heat signature, and triggers an alarm. Because of their sensitivity to both heat and movement, PIR detectors are often favoured for indoor security monitoring purposes.

Most home security experts would tend to agree that installing a security system with a high-quality PIR motion detector is probably the most effective option for preventing pet false alarms.  PIR sensors are configured to distinguish between the movements of small objects like a cat or a dog, and a full grown human. Because of the sophisticated engineering and sensitivity, PIR motion sensors are less susceptible to triggering false alarms, so they are generally the ones favoured by home owners. 

Active Infrared Detectors

Active infrared (IR) sensors are most often used in outdoor applications. These sensors emit an infrared beam, and that triggers an alarm when a person or object crossed the path of the beam.

Are other types of active motion sensors available to pet-loving home owners?

There are a number of other active motion sensors on the market that homeowners could use: ultrasonic, microwave and area reflective sensors. These all work in the same way that sonar works in submarines. The sensors emit energy waves, and measure the length of time it takes for the waves to bounce off stationary objects. When movement is sensed in the path of the energy wave, reflection times are altered and the sensor detects this movement. Ultrasound sensors use sound waves to detect movement, microwave sensors use microwave pulses, and area reflective sensors use an LED to emit infrared rays in the coverage area.

Mixed technology motion detectors Some sophisticated home security systems use multiple technologies to monitor properties. Dual technology home security systems might use a combination of PIR and area reflective sensors. The active sensor detects motion and the PIR sensor determines whether the movement is caused by a human or smaller animal. However, it should be noted that this type of motion detector won’t sound an alert/alarm until both sensors are tripped by movement.

Minimising false alarms when you have pets

No home security system, however sophisticated and expensive, is infallible. Every alarm system has its own peculiar vulnerabilities. Yet, there are things you can do to minimise the number of false alarms. Before you plough on and purchase an alarm system, you might want to consider these:

  • Pets are more likely to trigger false alarms when the security system uses active motion detectors.
  • Passive infrared motion detectors are more reliable because they use heat to distinguish between human and pet movement.
  • Even the most pet-friendly burglar alarm will trigger false alarms if the motion detector isn’t installed and placed correctly. The most important point to consider is coverage area.  
  • Look at your pet’s behaviour. What does it get up to during the day and where does it like to play? Certain types of behaviour could potentially trigger an alarm, so bear these in mind, especially if you’re thinking about using active motion detectors. If your pet likes to sleep on the sofa, or play on the stairs, make sure you point the motion sensors away from these activity areas. If that is going to be problematic, then keep the animals out of the sensor zones when the alarm is armed.
  • Keep the pets away from the motion sensors. Install them out of reach of pets – ideally 5 or 6 feet from floor level, but remember, cats like to climb on things and jump.
  • Pets have a lower centre of gravity than humans, so place motion sensors near to room ceilings so that area coverage starts a few feet off the ground. The sensors will still detect humans, but, generally, not your pet.
  • If your pet is pampered and heavy, they could well be approaching the minimum weight needed to trigger the sensor. If that is the case, mount the sensors upside down so that they point towards the ceiling, and not the floor. If you go down this route, then test the coverage. You want it to be low enough to capture human movement, but high enough to avoid your pet triggering the sensor. It might require a little trial and error, but it’s worth the bother.
  • Pets aren’t the only things that trigger alarms: heat and light can trigger sensors too. So don’t point motion sensors at windows which are in direct sunlight, and avoid having heaters in the coverage area. Glass allows heat and light to pass through it and could trigger the alarm: similarly, space heaters emit a lot of infrared energy when active. Some heaters have thermostats so they cycle on and off as the temperature changes.

Check your arming mode

If you’ve taken every precaution, dotted every i and crossed every t and still find that your alarm is triggered by your oversized dog, then it might be worth considering using a different arming mode. Most security systems feature multiple arming modes, including ones called Night Arm, Arm/Stay or something along those lines depending on the make and model of the alarm.  In these modes the door and window sensors are armed, but the motion detectors are disarmed.  This allows both you and your pets to move around inside your home. The alarm will only be triggered someone opens a door. 

This is probably OK to do whilst you’re in the home, but not great when you’re out. It’s not an ideal solution by any means, as you’re taking the motion sensor out of the equation by doing this, but if all else fails, look on it as a last resort.

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