According to the comments, the problem isn't garbage cans, and it's not confined to Clinton Street.
One reader has a mouse problem on Montague Street! Other readers explain why you get rat problems, pinning the blame on unscooped dog poop.
Whichever is true (all of them?), each reason seems exacerbated by the snow: garbage pick-up had been all screwed up when curbs were buried in mountains of black snow, and dog owners, for some mysterious reason, stopped picking up their pets' shit when snow was everywhere, burying it in a powdery deception soon exposed by the thaw.
Thanks Mother Nature, Department of Sanitation and dog walkers: now the rich people have rats. Next they'll get bedbugs.