Well most of the time Chip monks have lighter colors than squirrels,but u can tell by the bushiness of a squirrels tail between the almost roundness of a Chip monks.
Chipmunks are much smaller and have shorter fur and tails. See the links below.
Chipmunks don't generally infest the upper structure of buildings. They prefer ground boroughs or holes into your cellar. However, squirrels prefer the top level in a structure. They tend towards...
During the breeding season, you can occasionally see the teats on lactating female squirrels, and the enlarged testes of male squirrels. They look the same, however.