Gum (Spearmint flavor, Stride): Very small, does not make a discernible noise when it makes contact with the cage. Small chance of hitting bird, which does slight wing damage but also shuts it up for about 1-4 minutes.
Empty Iced Tea Carton (Publix brand, 1/2 gallon): High success rate. Makes a huge noise when thrown at bird's cage. No chance of hitting bird. Scares it silent for about 7-12 minutes. If the empty carton lands near bird's cage then add on 100% increased time in bird silence.
Textbook (Conceptual Chemistry, Third Edition): High success rate but also high risk of critical damage inflicted upon bird. Double this if the cage gets knocked over. Triple this if you break and shatter window near the bird's cage. Quadruple this if you hit the bird.
In my spare time I stare at a light for a few seconds then look around...