I don't go out of my way to kill insects, but if someone wants to boil insects for food, I'm not going to have any moral qualms with it. I don't see how crustaceans are much different.

Boiling is supposed to be painless and it’s meaning behind “boiling a frog alive”.

My small experience with being burned by hot or acidic liquid tells me exactly the opposite.

The anecdote is specific to frogs (and animals with similar sensory systems), and specific to boiling by increasing the temperature in small increments.

It's also a myth: https://en.wikipedia.org/wiki/Boiling_frog

Interesting that early experiments involved removing the frogs brain as well.

A steam bath was considered to be one of the most painless forms of suicide for Roman patricians.

I have just heard about Seneca dying in a stem bath, but that was more by accident (he committed suicide by cutting his wrists but that was taking too long so he wanted the heat to speed up blood extraction. He however died of suffocation)

How was that suicide supposed to work? (suffocation like Seneca did?)