Birds have a strong sense of smell and can be deterred by certain scents. Common bird-repelling odors include:
• Peppermint
• Cinnamon
• Citrus fruits such as lemon, orange, and grapefruit
• Garlic and onion
• Vinegar
• Ammonia
• Naphtha
Other strong-smelling options include coffee grounds, cayenne pepper, clove extract, lemongrass oil, mint oil, eucalyptus, and tea tree oil. Effectiveness varies by species, and some scents may also be unpleasant to people, so use them with caution in ventilated areas.