Rats Deserting A Sinking Ship

[Chipchopper]

Is there any documented evidence to support this claim ?

[Mamyalynne]

Some history to the saying here

https://www.merriam-webster.com/words-at-play/like-rats-fleeing-a-sinking-ship-history#:~:text=Rats%20deserting%20the%20sinking%20Ships,the%20Rats%20will%20desert%20her.&text=This%20metaphor%20seems%20to%20have,abandoning%20or%20fleeing%20the%20vessel.

[Buenchico]

I suspect that if you were a sailor on a sinking ship you might well notice the rats trying to flee from drowning as you tried to make good your own escape but it's unlikely that you'd find time to record the event in writing (and even less likely that any such journal would then be preserved to provide evidence for the validity of the phrase).

This might be of interest though:
https://www.merriam-webster.com/words-at-play/like-rats-fleeing-a-sinking-ship-history