Fun fact: in the boiling frog experiment, the frogs were 'pithed.' Jam a stick in their skull and scramble their brain.

Frog spinal cords have a lot of reflexes. They'll use one leg to wipe a painful stimulus off the other. They'll jump. But they accommodate pretty quickly and won't get excited enough to jump out of slowly warming water. Gotta have a brain for that.

Recounted here: https://archive.org/details/studiesfrombiol00martgoog/page/398/mode/2up

Original ref: Goltz, F. 1869. Beiträge zur Lehre von den Functionen der Nervencentren des Frosches. Berlin, 1869, p. 127, etc Which is actually online: https://ia801200.us.archive.org/15/items/b22344937/b22344937.pdf