I found this image whilst browsing Di Overton's blog Designers Block,
curious I clicked the link and discovered that:
"the design is a deliberate one. A bird's diet consists of seeds and worms. As children, we gather worms for fishing by wiggling a shovel in the ground. With this birdhouse, the bird can wiggle his own worms out of the ground by simply landing on the house and letting the subsequent momentum do the work."
So what do you think? Would this actually work? I'm not so sure....
Anway if you want one they cost $190.00 from Areaware.