By tricking live fish into attacking computer-generated "prey," scientists have learned that animals like birds and fish may indeed have evolved to swarm together to protect themselves from the threat of predators.
"Effectively, what we're doing here is we're getting predatory fish to play a video game," says Iain Couzin, who studies collective animal behavior at Princeton University. "And through playing that game, through seeing which virtual prey items they attack, we can get a very deep understanding of as to how behavioral interactions among prey affect their survival."
Refinance activity continues to boom, fueling the home-loan market. Low interest rates have created a class of "serial refinancers" — those lucky enough to borrow at lower rates — and given them new opportunities to spend their freed up cash.
Settlement attorney Robert Gratz never used to be on a first-name basis with his clients.
"In the past, our practice was such that you'd see people, and that was the end of it," he says.
Gratz now sees the same faces all the time, of clients refinancing again and again — these days in the mid-3 percent range.