Some wild caught kings, and certain subspecies of kingsnake do require the "split brain" technique to get them to eat mice, but California King, and I'm pretty sure Brooks, and Blotched kings are all very good at eating mice from the get go. I have 8 cal king eggs and 8 blotched king eggs incubating, and I expect that they will take pinkies from the beginning with little to no hassel.
Corn snakes and king snakes both eat pinkies when young. But Corn snakes don't STAY on pinkies, they will eat mice and even small rats as they mature. So you might find that a hatchling might not be a good purchase, but a yearling or a two year old snake might be perfect for you.
I'm sure some of the experts at more than the species I named can mention exactly which species of kingsnake is a picky mouse eater. But even those, if you purchase them after they are established on mice, will probably never have a sudden urge to resort to lizards.
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~Sasheena
Ground Snakes
Kit, Kaboodle, Tantilla, Tantillas, Lightning, Kinkee, Maple
JCP
Dreamer
Rosy
Castle
Kings
Licorice, Bishop, Queenie, Jester, Tigris, Euphrates
Pandora, Phantom
Lady
Corns
Aphrodite, Athena, Hermes
Tiger
Amulet