According to https://en.m.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.m.wikipedia.org/wiki/List_of_animals_by_number_of... 800000 neurons

According to https://en.m.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.m.wikipedia.org/wiki/List_of_animals_by_number_of... 800000 neurons is the same order of magnitude as a cockroach or honey bee but less but less than the simplest mammals. I'm guessing this is partly the reason the researchers believe it's not conscious. It's also roughly the same number of neurons as a human fetus somewhere in weeks 10-13 (I can't find a good reference for this). Week 10 is around when you'd see a heartbeat for the first time so this is pretty early in fetal development. But many more neurons and we're quickly getting into an ethical quagmire.