Drinking duck

The drinking duck is a great physical ‘toy’ whose movement is made possible by the so-called evaporative cooling. The body of the drinking duck consists of two glass spheres connected by a tube. Inside is a liquid that evaporates even at very low temperatures. This means that even the smallest temperature differences can generate movement. When the bird dips its beak into the water, the evaporation cold creates a negative pressure and the movement starts.

How cool is that! Almost like a perpetual motion machine.

Caution!
Contents are flammable! Do not use near heat or flames. If the liquid comes into contact with the eyes, rinse thoroughly with water and seek medical advice. Use only under adult supervision. Not intended for children under 14 years of age.