BirdShield™在表面風乾後會殘留葡萄香味,此味道會刺激雀鳥三叉神經系統,令雀鳥產生輕微過敏反應,所以不會繼續逗留。BirdShield™ will leave a residue with a grape-like odor after drying. It stimulates birds’ trigeminal system allergic reaction mildly, so that they will not stay in that particular area anymore.