The motion sensor outside, randomly send notifications during the day when there is nothing visible to set it off. But at night it works fine and only notifies me when there is actual movement.

If the device is set for night only mode there should be very little traffic coming from the MS. If you didn't set it to night only mode this is expected. Its also very dependant upon the location, install, and FOV.

 

Keep in mind IR sensors are prone to false readings due to extreme temperature changes, wind, and reflected light. You will need to determine the above first and follow up with a solution that meets your needs. There are settings to reduce the level of sensitivity the MS will detect.

 

If that is not enough you can always use a old school trick and place a piece of card board of various thickness to reduce the FOV. Keep in mind the Insteon sensor is by no stretch of the imagination  a true motion sensor.

 

You wan't high reliability and less false alerts than you need to purchase the real thing.