What sets a gen 2 alarm off?

Very basic question but I have a 2012 platinum and was wondering what sets the alarm off? I was in a hotel in Colorado recently on a atv riding trip and at 330am in the morning I was woken up to my alarm going off. It's a fairly secluded area of Colorado so I shut the alarm off from my room and watched my truck for a bit. Got back in bed and it immediately went off again......I hoped out of bed and grabbed my pew-pew and went running down to the truck. Checked everything over and nothing was missing or had been messed with. I found this odd because I've never heard my alarm go off before even yanking on locked door handles, hooking my trailer back up, and loading the bed up all while locked and it's never gone off.....any ideas what might have happened?

 

Did you look under the truck? A reciprocating saw trying to cut the catalytic converters off will set it off. They could have been hiding under the truck and realized it wasn't going to end well after the second attempt.

 

Yes that was the first thing I thought too, there were no saw markes or cuts of any kind.

 

I dunno about the tundra but i had a problem with a car in the past doing that, it thought the hood was being opened. It was just a shitbox so i adjusted the rubber stops down farther on the hood to resolve it.