You know, I’ve read that stabbing them through their head doesn’t really kill them because they have distributed ganglia instead of one centralized brain.

You need to define what the word alive means first.

If you cut a roach’s head, it stays sort of alive in that the body responds when trying to touch it or expose it to harm but it won’t do anything if left alone. just standing still until eventual death.

A decapitated roach might still be able to “feel” pain but in my personal opinion - I am no expert in the matter - it doesn’t feel stress, trauma or have bad memory of the incident. Just pain and an appropriate reflex to it.

In this context “alive” means “still able to feel and process pain.”

How does the decapitated roach feel the pain? The processing unit has been disconnected from the source of pain.

No it hasn’t been. Cockroaches, lobsters, and other arthropods have a decentralized nervous system. They have ganglia throughout their entire body instead of one centralized brain. These ganglia can react to stimuli independent of the other ones.

scientificamerican.com/…/fact-or-fiction-cockroac…

So does this mean stab the lobsters or don’t stab the lobsters? I was raised on the NE shore and have cooked hundreds of lobsters, I used to do the trick of putting them face down and stroking the spine, that would work ok but they wake up when you move them to the pot. I started stabbing the lobsters a few summers ago after a chef I worked with told me I should be, but I wasn’t convinced it was a lot more humane and it’s not fun if there’s kids around lol.