I don't actually know how long they've been coming to our house but I would guess at 2 years now?? They leave in Autumn and come back in the Spring.
It all started when Tigger (our neighbours cat) would come to our patio door and sit outside looking in until someone let her in. Then at some point, Mr and Mrs Duck turned up, saw Tigger doing it and decided to do the same! They fly into our garden, waddle up the stairs and come to the window. Of course we don't actually let them come inside - Mum goes out and feeds them bread.
However the story gets better! This is what happened:
One morning Mum got woken up by some kind of knocking, confused and annoyed she left her bed and went downstairs to where the knocking was coming from. She went into the lounge and pulled the curtain back to find Mr and Mrs Duck on the patio. Mrs Duck was standing a bit further away but Mr Duck was right by the window actually knocking on it with his beak!!
I never knew how clever ducks were!
They arrived again after the long Winter two weeks ago when I was home, and I spent the whole two weeks trying to video him when he was knocking but I always missed it :( I even have several videos on my phone just of him standing there in the hope that he will knock!
The cutest part is that when Tigger the cat comes along Mr Duck thinks it's his duty to save Mrs Duck and starts quacking at Tigger (who has no intention of eating them anyway) but it does scare poor Tigger anyway.