To anthropologist Helen Fisher, dopamine and other brain chemicals seal the deal as positives associated with adoration kick in, even as that part of the brain associated with fear and anger quiets. Those who maintain amour's illusions about their spouses report being more happily married, says Fisher. "In this case, self-deception is one of nature's gifts."

Question: Why might a submarine skipper seek out a colony of "killer" shrimp, such as the snapping shrimp "Alpheus heterochaelis" or the peacock mantis shrimp "Odontodactylus scyllarus"?

Answer: The snapping shrimp goes after prey by snapping its oversized claw nearby, expelling a jet of water and creating noisy collapsing bubbles (cavitation) that stun or kill the intended meal, says Jearl Walker in "The Flying Circus of Physics." The pressure variation here can be so severe it sets off a flash of light — "sonoluminescence." The oceans are indeed alive with sound and in some places so much sound is produced by shrimp that a submarine can avoid sonar detection by hiding next to a hungry colony.

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Send STRANGE questions to brothers Bill and Rich at strangetrue@compuserve.com, co-authors of "Can a Guy Get Pregnant? Scientific Answers to Everyday (and Not-So- Everyday) Questions," from Pi Press.