Grandpa says to the little boy: ‘See that little white string thing? It's called a tendon. If you pull it, the chicken foot opens and closes. Try it.’

The children book "Tom" is a story about a boy named Tommy and his grandfather. The two of them do different things together; including hanging out in grandpa butcher shop. The cover of this children’s book shows the grandfather smiling at his meat counter with a row of dead chickens hanging upside down in shackles. 

http://www.upc-online.org/summer2001/tom_alert.html

It reminds me a time when I was a little girl. I was in my grandparent’s kitchen, hanging out with my grandfather who was preparing something for dinner. He was pulling out the feathers of a bird on the kitchen table. I was so fascinated that I called my cousin to come and watch grandpa killing a penguin.

Scientists have discovered how to make chickens lay eggs containing drugs inside.

http://www.ananova.com/news/story/sm_556649.html