Optical illusions and brain teasers are a fun way to trick yourself or others and keep your mind sharp. Most people look at an image that makes them do a double take—finding it necessary to take a second look at what they might’ve seen. This brain teaser features adorable dolphins that are sure to perplex the mind.

How many dolphins are in the picture? Surprisingly, there are 17 dolphins. Some are hidden, in plain sight, while others are hidden more inconspicuously. Some are camouflaged within each other. The first row has 5 dolphins. The second row has 6, as does the third row.

At first glance, there are only a few dolphins. However, after a few seconds, the eyes and brain start registering more little dolphins until, eventually, 17 become apparent. However, it’s interesting to note that it’s actually incredibly common for people to have missed a number of dolphins at first glance. Even if you missed that one, there are others you can try.