Pigeons: not the most beloved animal. They're called the rats of the sky. Rats with wings. Gutter birds. Flying ashtrays. Gray cloud-dwelling trash-monsters. (We may have made the last one up.)

They poop everywhere. They make horrible cooing noises at six in the morning. They congregate in city centers and fly at you in swarms. They're horrible.

They're also—and we know we're going to blow some of your minds here—they're in the same family as doves. Yeah: the symbol of peace and the symbol of urban infestation and white splotches on your parked car are basically cousins.

And in On The Waterfront, they're practically symbolic twins.

Joey Doyle, himself a saintly symbol of goodness and innocence, likes to keep pigeons as pets on the roof of the apartment building where he lives. This seems like a pleasant hobby…and it also shows us that Joey is a nurturing sort of guy.

But there's a downside to being a pigeon—or being Joey. You're easy prey. Johnny's gangsters shove Joey off a roof and, later, a kid named Jimmy kills all the pigeons in order to get back at Terry for snitching (Terry takes care of the pigeons after Joey dies). So, pigeons symbolize goodness and innocence, but also the vulnerability of being good and innocent.

At one point, Terry says to Edie:

TERRY: You know this city's full of hawks? That's a fact. They hang around on the top of the big hotels. And they spot a pigeon in the park. Right down on him.

Hmm. Something's preying on these innocent lil' pigeons? Your metaphor-alert should be beeping like mad right about now.

The hawks are people like Johnny Friendly and Charley—predators—while the pigeons are defenseless good guys like Joey and Kayo Dugan. The pigeons just don't have big enough talons to defend themselves.

But there's even more to the symbol of pigeons than innocence and vulnerability. If you're up on your 1950's mob slang, you'll know that the phrase "stool pigeon" is synonymous with "police informer."

And that, of course, is exactly what Joey, Kayo, and Terry are. Joey and Karo get attacked by the mob "hawks" for their pigeon-like behavior, but Terry ends up getting away with little more than a bloody nose. In a rare Discovery Channel turn of events, a pigeon takes on a flock of hawks…and triumphs.