Yes, the Motion Sensors from the SimpliSafe Wireless Security System will generally not detect small pets (less than 30-50 pounds). If they are larger, your pet may set off the Motion Sensor and cause a false alarm. Even if they are smaller than 30 pounds, you must make sure that they cannot get within 2 feet of the Motion Sensor. Place the sensor high up (usually 5 feet works well) and away from anything your pets might climb on. If your pets walk in front of the Motion Sensor coming down stairs or walking on a table or bookcase, they may set the alarm off. It’s a good idea to test the system with your pet and confirm that your pet is small enough to be around the Motion Sensor. If you have a large pet, please contact customer support for assistance. We can help you position the sensor so as not to detect your pet or disable your Motion Sensor so that your pet can move around freely. More about Customizing Sensors.