What does "generalisation" mean?
Generalisation 


  Generalisation is the phenomenon of an organism responding to all situations similar to one in which it has been conditioned.


or 


  Not biologically differentiated or adapted to a specific function or environment


This means that  the the rats responded to ethanol the same way that they responded to the training mixtures. 

Sources:


Mangan, G. L. The Biology of Human Conduct: East-West Models of Temperament and Personality. Oxford: Pergamon, 1982. Print. 
"Generalized." - Memidex Dictionary/thesaurus. Web. 04 Mar. 2016. 
"Generalisation." - Biology-Online Dictionary. Web. 04 Mar. 2016.