Every year, half a million horseshoe crabs are captured and bled alive by biomedical companies, according to a fascinating story in The Atlantic. The blood, colored baby blue because it contains copper, coagulates when it detects bacteria and can therefore be used to test for contamination. The crabs are strapped into harnesses, spiked with shunts, drained of up to 30 percent of their blood, and eventually released. "I don't know about you, but the idea that every single person in America who has ever had an injection has been protected because we harvest the blood of a forgettable sea creature with a hidden chemical superpower makes me feel a little bit crazy," Alexis Madrigal writes.