Crayfish (aka crawfish, crawdads or mud-bugs) are freshwater crustaceans, closely related to lobsters. And if you live in the South, you have had your share of crayfish boils, since most people don't relate to crayfish except as dinner.
So it was interesting to read how Daniel Cattaert, of the National Center for Scientific Research (CNRS) in Talence, France discovered that nocturnal crayfish have high levels of the neurotransmitter, serotonin.
Cattaert found crayfish responded the same way as humans when given an anti-anxiety drug (which affects serotonin levels) during a dark and light maze test after experiencing stress.
In essence, the crayfish were all adventurous and curious before the stress but kept to the dark areas after. Following treatment with the anti-anxiety drug, they ventured out into the far parts of the maze again without hesitation. Hmm... I guess the take home message for humans is Keep Calm and Stay the Course. Go Science!