Brinks Home security...Alarm goin off?

We recently had to get an alarm on our home. We believe our neighbors keep breaking in our home, 3 times in dec last yr. 1 time in Jan this yr....maybe 2 times like a few yrs b4 that too..then we got Brinks in the end of JAN this yr. They stopped but in the last 2 months, the alarm been goin off, maybe false alarm, i don't think so. Brinks been telling me that whatever been setting it off is in the dining area, which is where i walk in the front door. but nobody has broken in the house again yet. But every since those ppl broke into my home several times, i have had people watch my house, drive by jus to check. twice, 2 people told me they saw the same people, same description in my yard while i'm at work, this was the same day it went off also. What are they doin to set off my alarm without breaking into my home? i got every window covered, i have, door, everything. i jus don't get it.