The present disclosure relates to a bird-scaring device. The bird-scaring device simulates a predatory bird in flight. The bird-scaring device is comprised of an upper body segment, a lower body segment, a middle body segment with a pair of wings, a positioning element, a positioning element mount and an upper fastening element and a lower fastening element for the slidable positioning of the bird-scaring device. The bird-scaring device may have unexpected and unpredictable motion as it slides between the upper and lower fastening element, sways with the positioning element and pivots on the positioning element mount. The wings may project laterally from the middle segment of the body and also may move in the wind to simulate the natural flying motion of a bird. In this way, the bird-scaring device may generate unpredictable, realistic predator bird motion to dispel pest birds.