The benefit of motion sensitive devices offered by The Pigeon Guy is that they do not require the constant movement of still products and they produce better results. You can expect a fake predator or scare device to last about 3 days. You may get results from a motion sensitive device for about 2 weeks. There is also a concern for longevity when it comes to mechanical devices functioning in foul weather. Constant nest removal is generally a large part of this process.