The Ducks are Back in Town

For the second year in a row, a pair of ducks has decided to take up residence in our very small pond, quacking and waddling off whenever we disturb them. The nice thing about them is that they have done a a very capable job of eating all the string algae that was left over from the winter. The bad thing is that when they are done with the string algae, they will start digging in the yard. Usually by then, I am outside so much that I scare them away. I wonder if they are the same ones from last year?