We have cats so we are installing our SAW motion detector in a room where there is nothing for them to climb on/jump off of. The sales person mentioned installing the sensor upside when I placed my order. Do I need to do that? At what height should I be installing the sensor? Does the fact we have cats (who cannot do anything but really walk around the room or sit on an object less than a foot tall) affect what height the sensor should be installed at?