We had one of those alarms a few years ago. Salesman said there is a pet sensitive motion sensor that won't alert on small movements so we went with that so the cats wouldn't set it off. I found I could move really really slow and defeat it.
Found out our city pretty much ignores the alarm calls when we set it off by mistake, but our roof leaked and tripped the tire alarm and they did respond to that. We found out the previous owner used a license plate to repair flashing and it leaked.