Abstract: An automatic pet door, enclosed within a housing, having a pet door located in between two sensors. The two sensors are positioned on arms that extending perpendicular to the housing. An infrared beam extends between the two sensors. When the beam is interrupted, a signal is sent to a motor located on top of the pet door. The motor is in constant connection with a power supply. A rack and pinion device works in conjunction with the motor. When a pet walks in between the two arms and the beam is broken, the motor causes the rack and pinion device to engage with teeth found on the top portion of the pet door, thus causing the door to open. Once the pet walks through the open door and the beam is once again continuous, the door closes.