Swallows are often a nuisance to homeowners during nesting. The birds build mud nests under the eaves of houses, barns, garages and other buildings. Nests can often damage paint and woodwork, but the birds are protected by law. Swallows, their nests, eggs and young may not be injured or transported. The only way to deal with a swallow problem is to prevent them from nesting.
Attach bird netting to the eaves of the building using hooks. Use netting with 1.2 cm to 1.8 cm (1/2 inch to 3/4 inch) holes, which is sold at garden supply or DIY centres. Screw the 5 cm (2 inch) wire-fastening nail hooks for drop ceiling hanger wire attachments into the outer edge of the eaves every 10 to 15 cm (4 to 6 inches). Tap the end of the hook with a hammer to get it started in the hard wood and then screw the hook into the wood by hand. Attach the netting to the hooks and drape down.
Attach 3.7 cm (1 1/2 inch) wooden dowels to the outside of the house, garage or barn. Nail them parallel to the side of the house, 45 cm (18 inches) down from the eaves. Most wooden dowels are sold in 90 cm (3 feet) lengths so measure your house to decide how many dowels you need to run along the side of the house. Affix hooks to the wooden dowels at the same spacing as used for the eaves.
Pull the bottom of the netting tight and attach it to the hooks in the dowels. The netting now stretches from the hooks mounted in the eaves, 45 cm (1 1/2 feet) down the side of the house, and is attached to the wooden dowel hooks on the side of the house. Pull the netting tight so birds don't get tangled up in it.
Make a curtain of netting -- instead of attaching it to the side of the house -- by hanging it from the hooks on the eaves and allowing it to drape down. The drawback to this method is that birds could become trapped in the loose netting and the wind may tear it down. A net curtain should extend a minimum of 45 cm (18 inches) down the side of the house. The curtain of netting should only hang 7.5 to 10 cm (3 to 4 inches) out from the wall, so birds do not fly up under it.
Block all doors and entrances to garages, barns and sheds to prevent swallows from flying in. Hang netting off the doors or install a plastic-strip door cover.
Install fibreglass sheets under the eaves of the building. These can be expensive and must be professionally cut and installed, but they are a long-term solution to swallow nesting. The fibreglass makes a smooth, concave area under the eves that the birds cannot use to nest on.
Swallows live in colonies. The birds return to the same location year after year in greater numbers as the colony builds.