Thanks to everyone who sent in photos of harvester ants. The contest is over, and the winner is Mike Dekker. Mike will receive a free copy of The Book of Deadly Animals (that's what they're calling it in the UK) when it's published next year.
Mike also sent me these images of the black widow in his garage. The purple plastic storage container in the background makes the widow look almost green.
Black Widow Bite -- a story from The Red Hourglass