Small mammals (4)
(Other definitions for hares that I've seen before include "Fast-running animals" , "Rabbit-like creatures" , "Fast animals" , "Long-eared animals" , "Fleet-footed animals" .)
(Other definitions for rats that I've seen before include "Snoopy's imprecation - vermin" , "were piped away" , "Annoyed expression" , "Heels" , "deserters" .)