This Bram Stoker award winning book is excellent and certainly deserves the award.
A seemingly mild mannered scientist creates a race of creatures designed to cull the human race. He believes they will kill certain 'immoral' or 'excess' people. But the supposedly stupid creatures develop a culture of their own and soon begin to disobey him. A number of innocent people are caught up in the middle.
The plot sounds cliched, but it is in fact a very original book with many unexpected twists and turned. I really loved it.