Itsy bitzy Spider was a real pain in the ass when they decided to make a home in a smoke detector

It started with a false fire alarm which took several days to track down and find  seems the fire alarm at a institutional customers group home was just going off randomly to make matters worse it was a conventional system which meant looking for the activated device or red LED lighted solid on the smoke detector None of which could be determined.

 The system had some older ESL smokes on it which I immediately replaced  as they are known trouble makers and have been known to go into alarm with out there LED locking in and the system settled down for the night till next morning more false alarms  thats when I found corrosion in the bathroom heat detectors and replaced them and again system seemed to settle . It was fine for 12 hours then another false  I suspected the pull station on the zone  which had been bumped numerous times and I have seen them cause random false alarms as no LED was lighted on any of the I3 System Sensor smokes  or older System sensor smokes which very rarely ever cause a problem. But thats when it really get weird. I take off the pull station and loop still shows it is being supervised despite fact the resistor is missing  as its attached to the pull station .This meant there was a 2nd resistor which was screwing with system that was improperly added to loop.  So I start looking for it and start taking every device apart thats when I find the trouble maker.

One of the smokes in bedroom 2 # has a spider web in it partially blocking the sensor and causing the false. But why was the LED not locking in? to make matters even stranger once I pulled the smoke out of the loop it was now showing a supervision problem no resistor? Hey wait a minute the I3 where never built with an in line resistor yet this unit appears to have one put it back in line its supervised.
Very strange apparently the spider managed to short out something in the smoke causing this issue.
I have contacted System Sensor and sending them the unit to inspect as they are just as curious as I am as to how this spider caused the problem when there are screens etc to prevent this kind of issue.
But thankfully the problem has been found and if it ever happens again I will know to better check all smokes on line when a false occurs and no LED is locked in .