When we hammer nails into wood, they're usually difficult to remove. So why do woodpeckers seem to have such an easy time?

 

University of Antwerp researchers set out to answer. They took high-speed videos of two black woodpeckers drilling into hardwood tree trunks. They then analyzed the footage frame by frame. 

 

The research team found that woodpeckers move their upper and lower beaks independently.

 

"Once the tip of the woodpecker's bill hits the wood, the bird's head rotates to the side ever so slightly, lifting the top part of the beak and twisting it a bit in the other direction, the videos reveal," Science Magazine reports. "This pull opens the bill a tiny amount and creates free space between the beak tip and the wood at the bottom of the punctured hole, so the bird can then easily retract its beak."