When Philip Stoddard eyes the fish in his research tanks, he's not admiring their graceful movements—he's wondering which ones are liars. 

Stoddard, a biologist and expert in electric fish at Florida International University in Miami, studies when fish are deceitful, and how other fish detect their fibs.   

Many animals communicate through an impressive array of techniques, from growling to changing colors to spraying chemicals in the air. So it's unsurprising, Stoddard says, that not all of that communication is honest.

One of the “fundamental remaining mysteries of animal communication” is how animals know to trust—or distrust—their fellow creatures, Stoddard says. (See "How Fish Make Themselves Invisible—Mystery Solved.")

In fact, says Stoddard, animals often deceive with the same calculations that we do: to manipulate others. 

“A young woman of any species can tell you that they don’t trust guys to be