Co-Evolution (Food Chain Wars Book 1)
Nice pseudo-asteroids, he lied.
Also:
Another intelligent species existed on Earth long before human kind. They had a taste for human flesh and slaughtered humans by the thousands. Human kind advanced, built great cities, and learned how to defend themselves. A stalemate ensued, and a truce was negotiated, with one human a week offered as food. What better humans to offer than criminals?
…
The word is “humankind.” One word.
If they existed long before humankind, where did they get the flesh from?
Ohhhhh, good catch, Johno!
Time travel, duh.