A male orb-web spider leaves behind a post-coital parting gift that helps to ensure that subsequent offspring are his?the tip of his genitals ? in the females' sexual orifice.

Sniper detection systems follow the supersonic trail of a bullet back to the gunman.

Blue whales sing to find mates and call to each other in distinct dialects to stay together in herds, according to new research. The finding could help with efforts to protect this endangered species.

Our closest invertebrate relative, the humble sea squirt, can regenerate its entire body from just tiny blood vessel fragments, scientists now report.

Vice President Dick Cheney's diagnosis of a blood clot in his leg has focused needed attention on this common and potentially life-threatening problem, heart experts say.

An international group of scientists has expanded the universal language for the genes of both disease-causing and beneficial microbes and their hosts.