Not that human beings couldn't equal them or even surpass them in ferocity, if necessary. But the Rats had nearly a thousand years of progress over Earth. Their Industrial Revolution had occurred while the Angles and the Saxons and the Jutes were pushing the Britons into Wales. They had put their first artificial satellites into orbit while King Alfred the Great was fighting off the Danes. They hadn't developed as rapidly as Man had. It took them roughly twice as long to go from one step to the next, so that their actual superiority was only a matter of five hundred years, and Man was catching up rapidly. Unfortunately, Man hadn't caught up yet. The first meeting of the two races had taken place in interstellar space, and had seemed friendly enough. Two ships had come within detector distance of each other, and had circled warily. It was almost a perfect example of the Leinster Hypothesis; neither knew where the other's home world was located, and neither could go back home for fear that the other would be able to follow. But the Leinster Hypothesis couldn't be followed to the end. Leinster's solution had been to have the parties trade ships and go home, but that only works when the two civilizations are fairly close in technological development. The Rats certainly weren't going to trade their ship for the inferior craft of the Earthmen. The Rats, conscious of their superiority, had a simpler solution. They were certain, after a while, that Earth posed no threat to them, so they invited the Earth ship to follow them home. The Earthmen had been taken on a carefully conducted tour of the Rats' home planet, and the captain of the Earth ship--who had gone down in history as "Sucker" Johnston--was convinced that the Rats meant no harm, and agreed to lead a Rat ship back to Earth. If the Rats had struck then, there would never have been a Rat-Human War. It would have been over before it started. But the Rats were too proud of their superiority. Earth was too far away to bother them for the moment; it wasn't in their line of conquest just yet. In another fifty years, the planet would be ready for picking off. Earth had no idea that the Rats were so widespread. They had taken and colonized over thirty planets, completely destroying the indigenous intelligent races that had existed on five of them. It wasn't just pride that had made the Rats decide to wait before hitting Earth; there was a certain amount of prudence, too. None of the other races they had met had developed space travel; the Earthmen might be a little tougher to beat. Not that there was any doubt of the outcome, as far as they were concerned--but why take chances?