We always declare and pay duty. One recent trip down, I packed a Solar Bear with ribeyes from our farmer friend. We connected from American to Cape Air, on separate tickets. Our connection, after rechecking all our bags, was a little tight. I told the security guy I had meat, but that wasn't good enough. He made me remove every single steak, packed like a jigsaw puzzle. Then I had to repack, all while racing to catch a flight. At least they arrived with me, which none of our checked bags did. Not sure which bags, if any, get transferred these days, as we have been using Cape Air coupons.