Alarm malfunctioning.

My car alarm has been going off all morning - nothing seems to be setting it off (it's not particularly sensitive so I doubt it's the wind?). It is parked in a particularly windy spot though.
What is weird is that the hazards aren't flashing - it's just the siren

Is this a sign of something in particular?
Best next step?

Backup battery needs replacing?

Check it didnt get wet over the weekend ... we had some pretty bad ass wind over and horizontal rain shit going on .... might wanna check the electronics aint water logged ..

or for a more permanent yet satisfying solution use a hammer