Capitalizing on the motion of spindly arms to deter pest birds, another device to birdproof your property is the Bird Spider. The spider's stainless steel “arms” bob and weave in the breeze, creating a visual distraction zone. Ideal for boats, light posts, AC units, signs, docks, and any other areas where pest birds tend to congregate. These are typically available in 2’, 4’ 6' and 8’ diameters to cover large areas and deal with various bird types--including pigeons, seagulls, cormorants and crows. Spiders are easy to install and have no moving parts. The best spiders have a U.V.-protected polycarbonate base.Still another bird scare device is the more sophisticated Scarecrow. This motion-activated sprinkler sprays a stream of water each time it senses a bird's motion. The combined effect of water spray, the Scarecrow's moving head and the sprinkler sound--all work to effectively birdproof an area. Birds soon get the idea that the area guarded by the scarecrow is to be avoided. Scarecrows are ideal for keeping pest birds out of gardens, backyards, pools/spas and other open spaces.No list of bird proofing devices would be complete without mentioning the ever-popular Bird Spike. These come in strips of menacing-looking spikes that keep pest birds from landing. Bird spikes are ideal way to keep pest birds from landing on roof peaks, window ledges, I-beams parapet walls, awnings, canopies, signs and gutters. Some manufacturers give you the option of rigid U.V.-resistant unbreakable polycarbonate spikes or stronger, more durable stainless steel spikes. While they may look they would impale a bird, the blunted spikes are actually harmless, as birds just refuse to land on or near them. Spike strips usually come in 3”, 5” and 8” widths. Their non-reflective metal finish makes them barely noticeable. If you have a curved surface you want to protect, one manufacturer makes a no-gap spike that bends for easy installation.The next bird proof deterrent doesn't look threatening or even move. It just exploits the physics of bird toes and gravity. Known as Bird Slopes, these clever devices--composed of angled PVC panels--simply deny birds the ability to land or perch. Bird slopes have been proven effective against swallows, starlings, pigeons, seagulls and many other types of birds. They are easily installed in ledges, eaves, beams and other 90-degree areas where pest birds often gather. The best panels are formed from U.V. protected PVC for lasting sun and weather protection.A simple, but effective way to bird proof large areas is Bird Netting. Typical mesh sizes include in 3/4", 1-1/8" and 2" to exclude a wide range of birds and bird sizes. Netting is most often used to protect fruit trees, crops, and vineyards. Choose heavy-duty netting to prevent pest birds from getting into aircraft hangars, large garages, factories, and warehouses. For netting that lasts, opt for U.V.-stabilized, flame resistant and rot and waterproof material. To bird proof horizontal surfaces, try Bird Gel. You apply it with a caulking gun in a zigzag pattern and when it dries, it leaves an icky surface birds hate to land on. The chemical is non-toxic to both humans and birds. Recommended for conduit, pipes, ledges, I-beams, and parapet walls, these gels dry clear. The best gels work through a wide range of temperatures--from 15F to 200F. For best effect, apply the gel every six months.Wish you could just zap those pest birds? You can with Electric-Tracks. Birds land on these and get a harmless electric jolt that "persuades" them to leave. Easily installed on flat or curved surfaces, the better tracks feature a flow-thru design to prevent water from collecting around them.Growers and vintners love the next category of bird deterrents. Called Misters, they birdproof large areas by releasing a super fine mist of methyl anthranilate into a bird's flight path. The chemical is a harmless grape extract. The systems come in a variety of dispersion systems to deter pigeons, starlings, sparrows, crows, geese and blackbirds.