Robot rat bullies real rats into depression… for science!

Usually before any drug is used in humans some sort of animal trials are done. The trouble is that the same disease has to be generated in the animal model. In the case of developing antidepressant drugs, rats with depression have to be created. This is normally done by giving them shocks or make them swim continuously. This is not how a human gets depression.
Humans are depressed by macho guys bullying them or make them feel small.

Enter the super rat the Ratbot. Guaranteed to give inferiority complex to the best of rats.

https://www.extremetech.com/extreme/148363-robot-rat-bullies-real-rats-into-depression-for-science