![mirror mirror in my tank whos the biggest fish of all](https://utterbuzz.com/wp-content/uploads/2024/09/mirror-mirror-in-my-tank-whos-the-biggest-fish-of-all-640x360.jpg)
Researchers have demonstrated that bluestreak cleaner wrasse (Labroides dimidiatus) checked their body size in a mirror before choosing whether to attack fish that were slightly larger or smaller than themselves, saying it was the first time for a non-human animal to be demonstrated to possess some mental states that are elements of private self-awareness.