The biggest difference between first-line hamsters and third-line hamsters is the eyes. Black eyes may be first-line or third-line, but red eyes will only be first-line. There are no red eyes in third-line hamsters. First-tier hamsters have a flat body and feel like mochi, while third-tier hamsters have a more three-dimensional frame with a round body and feel like sausages. The first-tier hamsters are obviously larger than the third-tier hamsters.
The difference is most obvious when hamsters are just born. When they become adults, due to some acquired factors, such as nutritional conditions, living environment, etc. It may give the illusion that the difference in individual size is not very obvious, but generally speaking, first-line hamsters are slightly larger than third-line hamsters.
