why does my alarm go off two or three times a day? on 2007 Honda Odyssey

The alarm on my 2007 Honda Odyssey goes off just sitting in the drive, no one around. What's causing this? Even if we have doors open and are cleaning it or whatever, the alarm sets itself, and we open a door, and there goes the alarm. Very annoying!

Asked by for the 2007 Honda Odyssey