Drinking bird

Okay, so have you ever seen those toys that have a bird with a long beak that dips into a cup of water and then moves back up? That's called a drinking bird and it's kind of like a little science experiment.

The bird has a special material inside it that expands when it gets wet, causing the beak to dip down. But when the beak gets wet, it also causes the liquid inside the bird's head to move around, which makes the bird's center of gravity shift.

Because of this, the bird ends up tipping forward and its beak comes out of the water. This causes the material inside to contract, which makes the beak rise up again.

As the beak rises, the bird's center of gravity shifts back and it tips backwards. This starts the whole process over again and the bird keeps dipping its beak in and out of the water over and over.

It's pretty cool to watch, and it's a fun way to learn about how different materials can expand and contract when they get wet or dry.