How do “blue water boxes” from zoos and other places actually work? How can a small figure stand on the “blue water”?

Question

I have no idea what they are actually called, but I have one of them with two penguins on it, and I wonder how they stand on the blue liquid?

In: 5

Answer 1

Like the toy where the penguin figures float between clear and blue liquid? The blue liquid is denser than the clear liquid and the penguin figures have a density between the two, so the float on the border of the two liquids.