They didn’t have souls. Empty vessels made up the population of the planet. But that didn’t stop Earth from wanting to invade.
The soulless are the easiest to consume.
There’s no guilt. No afterthought. No regret. No thrill. No sensitivity.
That’s what they did. They consumed. And consuming something with a soul could be tiresome.
The soul, you see, will then consume from within. So one tries hard to not consume a soul.
If a soul consumes you, instead, than you will find yourself empty and alone. Forever.
And eventually you will again be consumed, from the outside in.
And then you will cease.
Cease to exist.
Cease to believe.
Cease to know.
But you will try hard to avoid that. By having a soul. And keeping it. And what do you do if you have a soul?
You consume a life force without a soul. Simple as that.
So the planet was appetizing for that reason, and that reason alone. All of earth could survive another year just by consuming the beings that had no souls, from the planet far away. But there would be nothing left on that planet, and then it would die. This was a small sacrifice, Earth felt, for the future of Earth itself.
Or, at least, the near future.
If you cannot see beyond the near future, then it doesn’t matter much. But Earth never looked through a telescope all that much, except to find a planet with beings devoid of souls. If Earth had the knowledge and wisdom to look farther ahead, they would see even more.
Vision would expand. Life would expand. And the planet would live forever.
Happy, and free, and full of souls.
Instead, they could not see that instead of a telescope, they were looking into a mirror.