Answer: Barn swallows are really persistent, even if you remove their nests - they will just rebuild again. There is a product called Bird X which is a clear gel or liquid that can be put on surfaces to deter them from forming their nest. It can last for a year or more. Or, you can hang a temporary curtain barrier over the nesting spot. Hang a curtain or net (plastic or aluminum foil) from a wire or two attached to the soffit 3 to 4 Inches from the wall and extending downward about 18 Inches. This barrier will keep the birds from nesting and can be removed when nesting time is over. Barn swallows will return to a nesting site year after year so if yo keeping them from actually building a nest this year, they may not return next year. Hope this works for you!
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