"TIL in 1998, a married couple was left behind during a diving trip to the Great Barrier Reef. Two days passed before anyone realized what had happened. Despite a 5-day search, the couple was never found. A dive slate was later recovered which read "... rescue us before we die...""
I'm sure it was observed that there was a wide range in the amount of time living rats would be found in water after something that would have caused them to fall in.
To establish what mechanism was causing the disparity it would be extremely easy to test a rats reactions to different scenarios without actually killing the rat, not to say they didn't anyway though.
The point is that information relating to potentially extending survival time in a disastrous situation is among the most valuable things to study. Can you not recognize why that would be important to understand?