Faulty Motion Sensor?

[TonyFleisher]

Is the sensor located near a heater (or vent)?
There are a variety of things that can result in false reports.
See this faq for more ideas:

FAQ: False positives on motion sensors

A few weeks ago I was having this happen all day with one sensor. Finally I just unconnected it. I will say the battery was really low. I haven’t changed the battery and reinstalled it to see if that was the problem yet or not.