So the theory goes...
The brain is the center of the nervous system in animals. All vertebrates, and the majority of invertebrates, have a brain. Some "primitive" animals such as jellyfishes and starfishes have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell.
Brains can be extremely complex. The human brain contains roughly 100 billion neurons, linked with up to 10,000 synaptic connections each. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body and target them to specific recipient cells.
Without one... are we better than humans?