[Someone]

> Even a mouse needs hundreds of millions of neurons to do what a mouse does.

Under the very light assumption that a mouse doesn’t have neurons it doesn’t need, a mouse needs whatever number of neurons it has to do what a mouse does, so that’s not saying much.

Reading https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n..., an ant has only 250k neurons and many reptiles can do with around 10 million.

That page also says 71 million for the house mouse. So what is it that a mouse does that reptiles do not do that requires them to have that much larger a brain? Caring for their children?

[tim333]

Mice seem to have quite a good representation of the 3d environment around them and motor skills. I had one in my flat run off an jump through an approx 1 x 2 inch hole 6 inches off the ground and about 10 inches from where it jumped from. Humans would probably have a job with that and I've not seen a lizard say seem to have similar ability to know its way around.

I daresay I don't think animals actually need some number or neurons. There's probably just a trade off between more giving better results versus being heavier and more energy consuming.

[HappMacDonald]

Mice do a hell of a lot more socialization than lizards, and mammalian socialization is more complex per individual (more competition, feinting, theory-of-mind-like strategies) than the eusocial insect strategies of "my body is the swarm, I just happen to be the limb I have direct control over".

[sdenton4]

Speed may be a factor - reptiles and mice live their lives at very different paces.