It might sound strange, but these animals have evolved in such a way that they don’t need a brain to survive. Instead, they rely on other systems within their bodies to perform basic functions like moving, eating, and reacting to their environment.
1. Jellyfish
Jellyfish are one of the most well-known animals that don’t have a brain. Instead of a brain, jellyfish have a simple nerve net. This network of nerves allows them to sense their environment and respond to things like light, temperature, and touch. Even without a brain, jellyfish can swim, capture food, and protect themselves from danger. Some species of jellyfish have existed for over 500 million years, proving that this animal doesn’t always need a brain to survive in the ocean.
2. Sea sponge
Sea sponges don’t have a brain, heart, or even a nervous system. So how do they survive? Sponges filter water through their bodies, capturing tiny particles of food like plankton.