Hidden Animals

How many animals do you see in this drawing?

You probably see a horse right away. If you change your perspective, you can find a frog as well!

Here's another hidden animal illusion. What do you see here?

In this case, most people see a rabbit first, and when prompted, they can also see a duck.

You'll find that you have a hard time if you try to see both animals at the same time. Your brain can only perceive one or the other at a given moment. This is attributed to the Gestalt effect—the idea that the brain perceives whole objects rather than individual attributes or parts. More specifically, this illusion illustrates a multi-stable perception effect. Ambiguous objects or drawings, like these, switch unstably between one interpretation and the other. Unfortunately, Gestalt theory only notes that this occurs, but does not provide neurological explanation for why it happens.