My first Florida king has always been mellow, but I handled her a LOT when she was little. Maybe that helped, but she was my first snake and I was and still am fascinated by her.
Then I got a cornsnake who was a little older when I got him and he did NOT like to be handled. He's never bitten me, but he was skiddish. I handled him regularly and within weeks he had mellowed and is now quite enjoyable to handle.
And my third snake, a new Florida king from Bluerosy, I haven't had him for very long but he seems quite mellow also and does not seem to mind being handled. But I plan on handling him regularly like I did with the first, because I like to take them out.
So from my very limited experience, it seems like regular handling (and ample feeding) is a good way to not get bit! But what do I know?
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1.1 Florida Kingsnake
1.0 Kisatchie Cornsnake