Bird netting has been successfully used to block birds from entering unwanted areas. It's a humane, low profile way of blocking out pigeons, sparrows, gulls, starlings and crows. It comes in a variety of stock sizes and custom cuts. You can generally choose from two mesh sizes to deter the species of pest bird that tends to invade your particular commercial building: a 2-inch mesh and 3/4-inch mesh. The best No-Knot Bird Netting has the longest guarantee on the market--10 years.