Hi, @BLUE666.
Thanks for reaching out!
Detection sensitivity determines how much movement is needed to trigger a motion event. If you want to be alerted only when a large object is detected, lower the sensitivity. Conversely, if your camera is monitoring a small area, increase the sensitivity to detect smaller movements.
Furthermore, you may visit this support article on how to adjust motion detection settings on your Roku Smart Home camera
We hope you'll find this information helpful. Let us know if there's anything else we could further assist you.
Thanks,
Roku Community Team
Reynan L.
Roku Community Moderator