Alarming sight

How to Annoy the Neighbours:
1. Arrange a weekend away.
2. Place some helium balloons near the motion sensor.
3. Set the alarm and go 250 miles away.
The neightbours had to come in and try and sort out what was wrong when our alarm went off. Nearest son was requisitioned to help but couldn't find cause.
It was only when I was eating my breakfast this morning, that I noticed the balloons were moving and switching the motion sensor off and on.
Hopefully that was the problem but the man's coming to check it tomorrow.