---
title: "Rat · Animals and other organisms · Entities · Simulation Hypothesis"
url: https://simulation-hypothesis.com/entities/rat
description: "About 200 million neurons. Rats release trapped cagemates."
license: https://creativecommons.org/licenses/by/4.0/
credit: "Ross Allan Dahl, Simulation Hypothesis (simulation-hypothesis.com)"
---

[Entities](https://simulation-hypothesis.com/entities) › Animals and other organisms › Mammals

# Rat

Rattus norvegicus

About 200 million neurons. Rats release trapped cagemates.

Neurons

200 million measured  · whole brain (isotropic fractionator) 

Herculano-Houzel S, Mota B, Lent R (2006). Cellular scaling rules for rodent brains. PNAS 103:12138-12143\. doi:10.1073/pnas.0604911103.

In the cerebral cortex (or bird pallium)

31 million

Herculano-Houzel S, Lent R (2005). Isotropic fractionator. J Neurosci 25:2518-2521\. doi:10.1523/JNEUROSCI.4526-04.2005.

## Evidence

* Rats free trapped cagemates. This has been interpreted as empathy-driven helping.  
Ben-Ami Bartal I, Decety J, Mason P (2011). Empathy and pro-social behavior in rats. Science 334:1427-1430\. doi:10.1126/science.1210789.

The [New York Declaration on Animal Consciousness](https://sites.google.com/nyu.edu/nydeclaration/declaration) (2024) finds strong scientific support for conscious experience in mammals and birds.

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