Kill the Crab Already!

I was buying some fish from my local fishmonger, when I overheard the woman in front of me say to the man behind the counter..."So, how do I kill a crab?" she asks."Boil it," he says."Won't that be painful?""I don't know.""What's the most humane way to kill it?""I can whack it on the head -- instant death," he says helpfully."Oh Lord, no!" she mutters, then asks, "can I freeze it?""I wouldn't," he replies."What am I going to do?" she wails, looking seriously distressed."Become a vegetarian?" I venture tentatively.She looks at me, her eyes narrow. I think I've offended her.Then she says, "I got it! My husband will kill it!"She picks up her crab and leaves.