Spike looked up. The technical bits had lost him, but he knew about bleeding. He'd had his fair share of cuts and grazes in the past. "Because it's messy," he said as he raised his hand. "And people generally don't like having to clean it up." He shook his curly-haired head. His mum, for example, didn't appreciate it anywhere near the carpet. "And because if blood is coming out, it means there's a hole for stuff to go in. And that's not necessarily good either."