Although it may seem unbelievable, there are a range of animals that live and reproduce in the world nature and they even do it without one brain or brain as we know it. Before have developed other types of systems allowing them to live a full life, and in some cases a very long one.
Instead of having one brainsome living creatures that we can find in the nature, They have groups of specialized nerve cells called ganglia that help them perform vital functions such as feeding, defending themselves or reproducing.
But surprisingly, most of them mindless animals on this list they don’t even have these types of specialized cells. When it comes to doing what they have to do to survive, these animals don’t think about it for a secondliteral.
Animals without brains: Sea cucumbers
This Echinoderms, relatives of starfish, are animals without brains. But they still have ingenious defense mechanisms. When they feel in danger, they are able to eviscerate themselves, that is, eliminate a large part of their internal organs, which quickly grow back.
Moreover, they have an amazing ability to do that interfere with the area in which they occur. There are those that have bright colors that indicate danger, allowing them to protect themselves without the need for a brain.
Animals without brains: Jellyfish
This amazing mindless animals They have a so-called neural network, a system of nerve cells that are interwoven throughout the animal’s body. It allows them to ‘sense’ the presence of food, predators or possible companions.
Animals without brains: Sea sponges
Las sponges are mindless animals, but they don’t even have a digestive, nervous or circulatory system either. Instead, they have many unspecialized cells that can migrate throughout their bodies. And become whatever specific type of cell is needed at the right time.
A surprising fact is that sponges without internal organs can sneeze. When something ‘irritates’ them, a sponge absorbs a large amount of water. It then contracts its body and sprays whoever disturbs it with a sneeze that can last up to 60 minutes.
Animals without brains: sea lilies
These creatures look like a colony of ferns that has grown underwater. But in reality they are animals that ‘root’ in the ocean floor and devote themselves to ‘combing’ the water to obtain floating food.
Son mindless animals and they seem like very delicate creatures. But they are actually strong enough to withstand the pressures of life more than 6,000 meters below the sea surface.
Animals without brains: starfish
Although they have no brain or ganglia, Starfish have a certain sense of touch, sight and smell. Each of the starfish’s arms can sense the world around it.
When one of the arms ‘smells’ something tasty to eat, the energy supply to the rest of the arms is ‘cut off’. Then it begins to attract the body to the food source. And they have an amazing ability to regenerate their limbs, so much so that a severed arm can grow a new star (parthenogenesis).
Animals without brains: Sea anemones
Lacking a brain and a central nervous system, the anemone has a neural network similar to that of jellyfish. But it specializes in foraging for food, so as soon as anything edible passes through its poisonous tentacles, it is immediately paralyzed and consumed.
After eating, the anemone throws the waste through the same opening through which it received it. Because the digestive chamber has only one opening that acts as the mouth and anus. Then this mindless animal moves its tentacles to clean itself and prepare for the next bite. 
Animals without brains: corals
Corals are known for their ability to create so-called reefs. This is nothing more than the ‘shell’ of a dead coral, combined with that of its neighbor, creating enormous multicolored masses.
although They seem like innocent animals without brainsCorals are actually fierce little warriors. When a predator approaches or another species of coral establishes itself in another species’ territory, the tiny polyps send out their tentacles to poison and sting the invaders.
Animals without brains: Ascidians
Las Ascidians are mindless filter-feeding type animals., which resemble glass tubes with two holes emerging from the seabed. Strangely enough, a newborn sea squirt looks like a tadpole and has a small brain and one eye, but cannot eat.
Once born, it swims to the bottom of the ocean, where it curls up, grows, roots and matures, taking in its eyes, tail and brain, which serve to nourish itself during that stage. .
Animals without brains: Sea urchins
Hedgehogs spend their lives crawling across the ocean floor in search of food, but that’s it They are animals without brains, there is no planning for it. If they find something nutritious, they eat it, if not, they continue looking. Defense is not a problem for these animals full of spines, which in some cases are poisonous.
Animals without brains: Portuguese warship
This creature is actually a colony of polyps that stick together at birth and stay together for their entire lives. Each of the creatures that make up the caravel specializes in one of the facets of survival, such as defense, reproduction, or nutrition. In the absence of brains, unity is strength.
As you have seen, the lack of a brain is not a barrier to survival. In fact the systems used by these mindless animals They are really very innovative in doing this. And also extremely successful.