Nature's Yucky: Gross Stuff That Helps Nature Work - Lee Ann Landstrom, Karen Shragg
A good pick for die-hard fan of gross-out factoids. There are some truly gross facts in here, but the author clearly explains that each gross behavior has a very specific and important purpose. It probably goes without saying that this is not recommended for squeamish or sensitive readers. There is a particularly gruesome section about how killer whales dismember and eat their prey. Pretty yucky!