Smoke detectors can detect much more than smoke

  2:30am  Instantly awake!  All of the smoke detectors in our Salem, Oregon home are going off.  BEEP, BEEP, BEEP!!! For close to 30 seconds then they turn off.  I jump out of bed and run into the hall between the kid's and our room ready to assess the situation and get the kids out of the house......Nothing, no smell of smoke, no crackling fire.  No indication of fire at all!  At this point, the sudden rush from being totally asleep to totally awake and high on adrenaline for no apparent reason has me more than a little irritated.

  Our home was less than a year old so the next morning I called our builder.  He said he had never heard of that and didn't know what to tell me.  I let it go.  The silly detectors performed properly for another 6 months and the same thing happened!  Middle of the night, sound asleep, BEEP, BEEP, BEEP!! for about 30 seconds.

  A few months later I got a call from one of my home inspection clients describing a similar situation.  I called the detector company.

  Within a few minutes I was describing the phantom alarms to a real person at customer service.  He guessed that a spider was causing these false alarms!  Our wired-in alarms had a little green light that attracts the spiders.  When the spider gets to crawling around and exploring the crevices it steps into the ionization sensor.  The sensor 'sees' the spider as smoke and sounds the alarm.  All of this sudden vibration alarms the spider who promptly finds a new place to explore.

  The best thing to do to (hopefully) prevent this arachnid exploration is to blow out the detector and sensor with 'canned air' every so often.  Spiders are territorial and if they are disturbed repeatedly they will find new areas to hang-out.

  It has been about a year and a half since the last false alarm.  I hope this insight answers some questions for those of you who have had similar experiences.