It looks like common names like "squirrel" or "chipmunk" that cover many different species are taken more as "squirrel-like animal" and "chipmunk-like animal". They are in the same family (Sciuridae).

Just be more specific and it is happy to count them. For example it counts Townsend's chipmunk, Eastern chipmunk, Siberian chipmunk, Douglas squirrel, Eastern gray squirrel, Western gray squirrel, and Red squirrel all as separate animals.