Hamsters! Not really. Each of my kinetic sculptures is a wooden machine powered by a constant force spring which must be wound. While visually interesting sculptures when still, they become truly fascinating when in motion. After a simple winding they entertain with motion and soft sounds for varying lengths of time. Increasing run times has always been a goal. Some will run for 1 1/2 hours while others keep moving for up to 24 hours! That is quite an increase over my original designs which stopped after 20 minutes.