Last night DR Jeanne asked: The cats sharpen their claws before dinner? Do you make them open the cans?
Annabelle's vet ad I discussed this. When cats are ready to eat, they sharpen their claws. I suspect this is a residual holdover from the long ago wildcat days when they needed to sharpen their claws to tear open a meal.
As soon as I say the word "treat," all three cats run to scratching posts.