Well, if you throw them starchy treats like your shitty potato chips or your ugly Lucky charms, they'll swoop down and snap them up. It is true. Also napkins, condiments, dirty diapers, etc. They are a very rapacious bird.
But if you throw up an Alka Seltzer (rumor has it) they'll end up quickly on the rocks. Dead. On account of they cannot throw up, and the expansion blows their valves out.
Whatever. If you are at a certain bar and Dan wants to buy you a drink...just smile and nod. Or if he tells you how he stepped outside for a smoke and one of your bikes is on top of the other. Or if he wants to give you money for the jukebox. Or follow you to your next bar and tip the band to play something with bicycles in it "for you", and tell you about how he parked behind the nearby porn store...Smile and nod, but don't commit to anything.