Japanese engineers have devised a robotic rat that bullies laboratory rats into a state of depression, creating a model of human depression they deem suitable for testing antidepressants. The research, published this month in Advanced Robotics, reports that continuous attacks in young and intermittent attacks (in response to movement) in older rats is most effective.
Ishii, H., Shi, Q., Fumino, S., A novel method to develop an animal model of depression using a small mobile robot. Advanced Robotics. 2013: 27(1) 61-69
Of further interest:
Robot rat bullies real rats into depression… for science! (Extreme Tech)