List of animals by number of neurons

This is a list of animals by number of neurons in their brain. These numbers are estimations derived by multiplying the density of neurons in a particular animal by the average weight or mass of the animal's brain

Overview
Neurons are the cells in the brain which transmit information to and from body parts. In the simplest organisms, they act only to drive the organism to respond to certain stimuli. In higher organisms, reasoning abilities come into play and we can see animals working collectively to achieve a similar goal. Humans are the only higher animals which are capable of abstraction, most likely as a direct result of the immense number of neurons present.

Alphabetically
Listed from A-Z

Numerically
Listed numerically from greatest number of neurons to least number of neurons