Hydra is a suborder of animals. Their bodies have a weak nervous system. In the animal world, hydra or nidarians developed the first nervous system. Nervous system emerges from their afferent neurons and joins to form neural network. Neurons do not have axons or dendrites and never form synapses. Mesoglia has one nerve plexus on either side. Nerves are attached to the epidermis and gastrodermis. Nerves are densely located in the mouth and foot. Neurons are connected to each other and to sensory cells and muscle cells. Sensory cells receive light, touch and chemical stimuli from the environment. Then through the nerve network sent to the muscle cells. Dr. Siddiq Publications