Pet-Friendly Alarm Sensors: Avoiding False Alarms

Pet-friendly (pet-immune) PIR sensors are designed to ignore animals up to a set weight - typically around 25kg - so cats and dogs don't set off false alarms. They do it by shaping the detection pattern to overlook movement low to the ground while still catching a person.

How they work

A standard PIR detects body heat moving across a room. A pet-immune PIR uses a lens and processing tuned to ignore the smaller heat signature of an animal near the floor, while still triggering on a human-sized target. Many let you set the tolerance to suit a cat or a larger dog.

Positioning matters

Mount sensors at the recommended height and angle so pets stay in the "ignored" zone, and avoid pointing them at stairs, cat trees or furniture a pet can climb - height is where pets fool a sensor. Good placement is half the job.

Other options

For homes with large or very active pets, you can also rely more on door/window contacts (which pets can't trigger) and use motion sensors only in rooms the pet doesn't access. What sensors do I need?

Add pet-friendly sensors to a custom kit.

Frequently asked questions

Will my pet set off the alarm?
Not with pet-immune PIR sensors, which ignore animals up to around 25kg. Correct height and positioning are key to avoiding false alarms from pets.

What weight do pet-friendly sensors tolerate?
Many pet-immune PIRs ignore animals up to around 25kg, and some let you adjust the tolerance for cats or larger dogs.

How do I stop my dog triggering the alarm?
Use pet-immune sensors mounted at the right height, keep them away from furniture or stairs the dog can climb, and rely on door/window contacts in rooms the dog uses.