Duck Duck Duck

And one more duck, if all goes well.  We have been having our house tuck pointed for about a year now, off and on. Please note how beautiful the brickwork behind this nest is, because it has all been reworked. Apparently the process of this tromped down the mint bed just enough for it to be attractive to a duck couple.
So here is what is cool about this (and what may be it's demise in the end)--we walk right by this every day, as do our dogs.  What made ducks think this was a good idea?  I am a bit worried that they will abandon it altogether for this reason, but the ability to watch small ducklings grow up and leave the nest makes me hope that I am wrong about this.  I am pretty fascinated by birds, and love seeing them in the yard, and am happy to have a few families raised here every spring and summer.