Animals by Number of Neurons
ADDPMP573Neurons are the cells that transmit information in an animal’s nervous system so that it can sense stimuli from its environment and behave accordingly. Not all animals have neurons, Trichoplax and sponges lack nerve cells altogether. Neurons may be packed to form structures such as the brain of vertebrates or the neural ganglions of insects. The number of neurons and their relative abundance in different parts of the brain is a determinant of neural function and, consequently, of behavior. The following list shows the number of neurons in the structure that has been found to be representative of animal intelligence.
African elephant = 2.57×10^10
Human = 8.6×10^10
Gorilla = 3.34×10^10
Chimpanzee = 2.8×10^10
Giraffe = 1.075×10^10
Brown bear = 9.586×10^9
Lion = 4.667×10^9
Raven = 2.171×10^9
Fox = 2.11 × 10^9
Capybara = 1.6×10^9
Octopus = 500,000,000
Pigeon = 310,000,000
Brown rat = 200,000,000
Nile crocodile = 80,500,000
Frog = 16,000,000
Honey bee = 960,000
Ant = 250,000
Box jellyfish = 8,700–17,500
Tardigrade = about 200
Sponge = 0