As of recently, one of them has become rather active even on the lowest sensititivity. I did appreciate the year I'd get out of the battery and that they're regular AAA batteries. It's constantly powering on my deck lighting when motion occurs in the middle of the night.
Mice? Moving vegetation of some sort?
You could try covering over part of the sensor window, like maybe the lower part? Aim it a little higher?
Outside motion detection can be a problem. A breeze comes along and moves some vegetation. Doesn't take much.
Something is setting it off though. Not really "false" alarm.
edit: Could get a game camera. I've better pestered this year by the likes of the critter below:
My Hue indoor drops off frequently and the outdoor is slower than my Z wave sensors. I don't have enough Zigbee to mess with trying make a bigger mesh just to support them. If I'm going to need to buy additional devices, I may as well go Z wave LR and just get rid of the last ZigBee holdouts.
The only other Zigbee I have is 3 Innr Zigbee 3.0 bulbs. Those don't really work well with hue sensors. I had to remove them to add the Hue, then add the Innr. From the stand point of building a proper mesh (yes, the Innrs are repeaters) They should have been first being closer to the hub and the hue sensors being the farthest away. Eventually even those Innr bulbs are going to be replaced with Nanoleaf matter bulbs.
The only other ZigBee I have is an Aqara G3 Camera/hub (which is it's own ZigBee hub anyway) and a P1 motion sensor, but those are bridged to Hubitat on matter. The P1 motion sensor is eventually also going to be replaced with a Zooz ZSE18 or Ring Gen2 Motion Sensor.
Got notice from zooz that the items needed to convert my ZSE70 to 12V wired operation are in the mail and received USPS notification also. Will be converting to wired operation soon.
Just an update. I have had the ZSE11 included, and it has been working very well for about a week now. I replaced the Aqara P1 with it, but installed it where the Hue indoor sensor was, and moved that to where the Aqara was. I wanted to compare the Zooz and Hue side by side. What I'm finding goes against the common belief that Zwave motion sensors are slower. This thing is faster and more reliable than the hue ever was. I will give the disclaimer that at the time of the switch my Zigbee mesh has become relatively small. The Zigbee mesh was bigger when the Hue sensor was installed, but I have never been thrilled by its performance. Additionally, the ZSE11 is paired in LR mode. The Zooz is rock solid. I have no doubts that it will work as intended whenever I enter that room. With the Hue, I was always a bit skeptical that it would work. I will add that I have not yet incorporated the lux-based rules, so I really don't know how accurate the lux readings are.
Soon, I will go ahead and replace that Hue Indoor Sensor with either another ZSE11, or a ZSE18 (just because the smaller form factor is less objectionable to my wife). There is one remaining Hue Outdoor sensor, that one is also destined to be replaced. That will be replaced with the ZSE70. Once this round of replacements is complete, I will have a decent assortment of devices I'm no longer using. I plan to sell at reasonable prices (plus shipping costs), these Hue sensors will be among those items.