Re animal studies:

You have no right to constrain a rat and experiment on him.

Observe him in the wild. You affect the experiment too much. The studies say more about personality flaws in the researchers than about rats.

See the passage in Feynman's [Cargo Cult Science](https://www.lhup.edu/~DSIMANEK/cargocul.htm) on rat studies.

Also, recently there was a study that showed pain measurement in rats was influenced strongly by the gender of the experimenter.

Just observe. Do not tag, maim, poison, tranquillize, kill. Learn to talk to rats.

Rats laugh in a pitch range too high for humans to hear. Rats live rich intellectual lives with independent individual thoughts. Rats are trying to communicate. Drop preconceptions and try back.