Red widow spiders have entirely red-brown bodies, with the exception of their black abdomen. ©Florida Division of Plant Industry Archive / CC BY 3.0 US, via Wikimedia Commons – Original ...

Hour 1: The thighs, back, and shoulders are usually ... than a rattlesnake — the black widow spider. What happens when it bites? All black with a red hourglass, just bigger than a paperclip.

Black widows are notorious spiders identified by the colored, hourglass-shaped mark on their abdomens. Several species answer to the name, and they are found in temperate regions around the world.