Motion detection is what allows the camera to detect and record your pets by monitoring real-time changes in the video feed.
You can adjust the motion detection sensitivity by going to the app's Settings, selecting Motion Detection, and then choosing Motion Detection Sensitivity. You can then adjust the level up or down.
If you notice that some pet activity has been missed, you might want to increase the sensitivity. If you're getting too many false alerts, try lowering the sensitivity. That should help.