Corolla alarm problem

[IanB2]

For the last four nights running, my 2019 Corolla’s alarm has triggered during the night, each time between about midnight and 2 am.  For the first three nights it triggered twice within about half an hour, so of course last night I was lying there waiting for the second time, but it only happened once.  No previous problems with the alarm, and having been around a fair bit during the daytime, I am reasonably confident it’s only happening at night.

I am away from home in Italy at the moment, and it’s parked on the street in bright sunshine during the daytime.  Also a few days ago I saw a medium-sized spider in the car.  Otherwise I am stumped as to explanations; no-one is tampering with it as the street is empty when it happens, and there is no passing traffic or other vibrations.

Any suggestions as to quick fixes I might try, as I don’t really want to get it looked at until I get home?

[FROSTYBALLS]

Could well be spidey triggering the interior sensors.

[furtula]

Locking with physical key should not trigger the alarm. 

[forkingabout]

Spider will be triggering the ultrasonic alarm sensors with its web spinning.

You need to remove the spider from the vehicle interior. 

You could also disable the ultrasonic sensors then arm the alarm system, this will disable the interior protection but leave the perimeter protected. 

[Jiff]

Could be a moth as they only come out when it's dark. It happened to me, I disabled the internal ultrasonic detectors as suggested. Once it's left the moth out it didn't happen again.