Confused by that headline? It's simple really – when drugs and medical devices are tested for contamination, a substance called Limulus amebocyte lysate (LAL) is used. LAL is made from the blood cells of horseshoe crabs, which are caught along the U.S. Atlantic coast, drained of 30 percent of their blood, then returned to the water. Although the majority of the crabs survive the process, it has been estimated that at least 30 percent do not. This, in turn, is affecting populations of the red knot, a bird that feeds on horseshoe crab eggs. Now, engineers from Princeton University have discovered that a substance from the skin of the African clawed frog could be used instead of the crab blood – with no harm done to the frog. No word on whether eye of newt or wing of bat would work, too.