Masking Tape Obstruction
One of the ways to bypass a motion detector is to apply masking tape to the edges of the motion detector's viewing window. This should be performed when the motion sensor is inoperative for better results. Some motion detectors go into inoperative cycles or are controlled with remote controls. Although it can be done when the motion detector is operative by using other methods to get to the detector, this is more risky. Apply masking tape to the edges of the translucent plastic viewing window on the detector. Fill in the gaps between the edges by applying tape over the viewing window to cover the entire window. This will give the motion detector an unchanging view that will not trigger the detector when it is reactivated.
Crawling
Many people have pets and having a motion detector that rings every time a pet walks into a room when the detector is activated can become annoying. Some detectors are designed for homeowners with pets that leave room for smaller animals such as dogs and cats to pass safely under the motion detector's line of sight. In these cases, you can beat a motion detector by crawling along open spaces or wiggling across the floor while lying on your stomach. You must stay lower than the size of an average dog or this will trigger the motion detector.
Walls
The most efficient way to beat a motion detector is to determine which wall the motion detector is attached to. Most detectors have blind spots directly underneath, so the wall they are placed on is virtually invisible. To beat the motion detector, move slowly along the wall the detector is mounted to. Stay close to the wall and keep your arms at your sides to avoid making any motion the detector may capture. It can help to stay low along the wall to ensure you are out of the motion detector's line of sight. There may be motion detectors on the opposite wall, so you may want to locate all the detectors in the room before proceeding.
Paper or Cardboard Obstruction
Once you have reached the motion detector by either crawling to the detector or moving along the wall the detector is mounted on, you can place an obstruction in front of the detector. A piece of paper that is dark in color or piece of cardboard can be placed in front of the detector to serve as an obstruction. Although this method is slightly more risky than the others, it can serve as a last resort to beating a motion detector. The paper or cardboard must be moved slowly to the sensor and secured with pieces of tape gently to avoid sounding the alarm.