A small, low-lying town is being plagued by flooding problems. It seems that every week another creek is overrunning its banks and causing considerable property damage. In a fit of inspiration, the mayor approaches the city zoo, which happens to be home to a family of industrious beavers. The beavers lend their services out selflessly, building a series of dams, as needed, to protect homes and businesses. Grateful homeowners offer various forms of payment, which the beavers graciously decline.
Well, Frank lives next to a stream that's been acting pretty turbulent lately, and after seeing his neighbors getting dams built around their sections of stream, he decides that it would be prudent to get one also. He goes to the zoo and, after walking around a bit, comes across a brown furry mammal swimming in a pool.
"Hey, you!" he calls to the animal, who obligingly swims over. "I'm really scared that my house is going to flood. Can you come over and do something about it?"
"What do you expect me to do?" asks the animal, distractedly playing with a piece of fish.
"I dunno... chew down some trees, pack them together, keep the stream back... you know, beaver stuff."
"That sounds like a lot of work. What will you give me if I do it?"
"What? I thought you would do it for free. My neighbors didn't mention anything about payment."
"Nope. Not interested. Goodbye."
"What? But this is important, and I really need your help!"
The animal sighs and rolls his eyes. "Sir, I'm an otter. I think you have me confused with someone who gives a dam."