Systems and methods for detecting presence and movement of pests. Various embodiments of a pest detection system can be based on, for example, a beam-interrupt detector or a thermal imaging device. The beam-interrupt detection based system can provide functionalities such as counting of pests crossing a given beam. A plurality of such beams at different heights can also allow distinguishing different sized pests. The thermal imaging based detection system can provide functionalities such as tracking movement of pests. A recording can be triggered by detection of pest movement, thereby improving the efficiency of recording and reviewing information indicative of presence and movement of pests in a monitored area. Movement of pests can be monitored on a passive basis, or by providing a stimulus that induces movement.