A hedgehog can have between 5,000 and 7,000 quills. The inside of these quills is mostly hollow, with a series of complex air chambers that make them light but strong. With this Hedgehog Nanoblock Constructible Figure, you can use the smallest building blocks in the world to build your own hedgehog that will fit in the palm of your hand! A moderately challenging building set for beginner building block fans, this set features over 120 micro building blocks, allowing you to build in greater detail. Ages 12 and up. Level of difficulty: 2 (on a scale of 1 to 5, with 5 being the most difficult).