Which animal does not have nervous system?

Also know, which animal has no nervous system?

The only multicellular animals that have no nervous system at all are sponges and microscopic bloblike organisms called placozoans and mesozoans. The nervous systems of ctenophores (comb jellies) and cnidarians (e.g., anemones, hydras, corals and jellyfishes) consist of a diffuse nerve net.

which animal have nervous system but no brain? Sponge (Phylum Porifera) is a multicellular organism that doesn't have brain but have some kind of central nervous system.

Herein, do all animals have a nervous system?

All animals have a true nervous system except sea sponges. Cnidarians, such as jellyfish, lack a true brain but have a system of separate but connected neurons called a nerve net. Echinoderms, such as sea stars, have neurons that are bundled into fibers called nerves.

Why do animals need a nervous system?

Even animals that don't think have simple nervous systems called nerve nets that help them move. Your peripheral nervous system is made up of the network of neurons that spans your organs, muscles, and body. The neurons in both systems work together to help you think, survive, and change the world around you.