H.W.
I do not use the alarm when we have a babysitter present. I have heard of SO MANY stories of alarms going off when a door was accidentally opened, etc. and the sitter is unable to reach the parent. You don't want to do that to a sitter, believe me! We only arm it when we are all going to be out of the house; my stepmom sets their alarm at night and has set it off in the morning more times than I can count.