http://www.rollerfeeder.com

From their website:

"A RollerFeeder is a bird feeder that fully spins in a clockwise or counter-clockwise direction. The feeder allows small birds to feed while preventing squirrels and large birds from feeding. The feeder typically hangs directly off a tree limb, tree trunk (or any horizontal extension) and is best for birds such as chickadees, finches, nuthatches, titmice, and other small birds. When animals such as squirrels, raccoons, or large birds climb or land on the feeder, the outer shell, perch, and shaft sleeves spin. The fully rotational design prevents the unwanted visitor from resting or climbing about the feeder, and at the same time, closes off access to the feed ports. Afterwards, the shell quickly rocks back into feeding position and is ready for the next chickadee to come along".

The seed hopper remains upright (no spilled seed) no matter how much the outer shell spins around (I added that and can verify it from personal observation). I didn't take pictures or video during the first few weeks when the squirrels went crazy trying to get in. Wish I had.

http://www.rollerfeeder.com

From their website:

"A RollerFeeder is a bird feeder that fully spins in a clockwise or counter-clockwise direction. The feeder allows small birds to feed while preventing squirrels and large birds from feeding. The feeder typically hangs directly off a tree limb, tree trunk (or any horizontal extension) and is best for birds such as chickadees, finches, nuthatches, titmice, and other small birds. When animals such as squirrels, raccoons, or large birds climb or land on the feeder, the outer shell, perch, and shaft sleeves spin. The fully rotational design prevents the unwanted visitor from resting or climbing about the feeder, and at the same time, closes off access to the feed ports. Afterwards, the shell quickly rocks back into feeding position and is ready for the next chickadee to come along".

The seed hopper remains upright (no spilled seed) no matter how much the outer shell spins around (I added that and can verify it from personal observation). I didn't take pictures or video during the first few weeks when the squirrels went crazy trying to get in. Wish I had.