Concrete cinder blocks - free to good home

These little guys have been frolicking in my back yard for a while, but it's finally time to let them go. As a responsible owner, I can't just open the gate and let them out, so I'm hoping someone can give them a better home. Care is easy, just give them plenty of exercise. They like holding up heavy things for long periods. They come in all shapes and sizes, but I love them all equally.