Intruder detection mystery

I’ve been on a short holiday while having my boiler replaced.

late friday night, at about 11pm, the motion detector in my dining room triggered the intruder detector. However, there was no break-in. Neither front or back door was opened.

Also the motion started and stopped at 22.56… and didn’t recur

Mouse or glitch?

I woke up this morning to find my hall light on as motion had been detected and stopped 1 minute before my alarm went off on the Sonos.

I am going for glitch

hmm maybe it was a glitch. didn’t think a mouse could really trigger the PIR…

does anyone have a pet rodent they cant test this with?

although I’d actually rather it was a mouse as I’m not going to set up my newly purchased siren if it’s liable to go off willy-nilly

Since having my new ST installation for just over a week now, two of my motion sensors have triggered the intrusion detection. They were a single detection on separate sensors ( kitchen, garage). I am hoping it is only a glitch as if this is going to be a regular occurrence, using as part of an alarm system could be setting off nuisance alerts. I will have to look at another manufacturers sensor if it continues!

The only false motion alerts I’ve ever had were from a gen 1 ST motion. I’ve since stopped using that detector for security purposes. However, if any other motion would act up I plan to try using this smart app from @Mike_Maxwell I think it would do the trick to stop any false alarms.

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that’s interesting Greg, thanks

maybe there is already a siren app that requires more than a momentary motion to trigger. I will take a look

I would still be interested in any test results for small animals triggering the motion sensor. Dog, cat, fish, mouse etc

I can confirm that with ST Gen 1 motion sensor I got dozen of alerts and triggered alarms in my house. When my gen 1 kitchen triggers an alarm, I check my living room and all is well.

I also had similar false motion alert yesterday saying motion sensor picked up motion in living room so I have to rush home to check if everything was still ok. Glad it was. Don’t know what triggered it (small insect maybe) but wasn’t happy about it and concerned about the reliability of the sensors now.

Most common reason for false alerts in motion sensor is air of a different temperature. Heater comes on, a/c comes on, cloud goes across the sun, these can all trigger them. Insects also possible. See the FAQ:

However, there was an entirely different issue over the last few days which was random events being fired in SmartThings, nothing to do with the devices themselves. So it could have been that as well. :frowning:


I agree with this. I’ve got a motion sensor in my patio and I have it set to turn on the string lights for a minute when it detects motion. I have noticed that when there is a drift of air (it has to be a hot/cold mix) then the motion sensor turns the light on. Similarly, I have a motion sensor in my game room that was behaving the same way, then I figured that it was getting a direct blast from the A/C vent. I changed its position and it never gave me a false trigger again.