I feed my wild foxers in-shell pecans when in season and occasionally in shell peanuts (roasted, unsalted). Both have relatively soft shells.

I have thus far been too chicken to feed them in-shell almonds, hazelnuts, and walnuts because the shells seem so hard. I'm a neurotic helicopter squaddy who worries they'll hurt themselves on these. Am I being silly? Can yall verify that these varieties are safe for their teeth? I know my crew would be so stoked to have them.