Tis the alarm keypad.
If it's going off a lot, try inspecting the switch under the bonnet. The bracket is a tad flimsy and can get bent enough so the switch doesn't do switching things.
Also, I'm not 100% but will the alarm go off with low battery voltage too?
You have things in your glove box too, you absolute rebel. I don't use mine at all. I hate things slopping about and making noise.