How can I tell the difference between a shrew and a mouse?

The shrew is a small, mouse-sized mammal with an elongated snout, a dense fur of uniform color, small eyes, and five clawed toes on each foot. Its skull, compared to that of rodents, is long and narrow, and it lacks the zygomatic arch on the lateral side characteristic of rodents. The teeth are small, sharp, and commonly dark-tipped. Pigmentation on the tips of the teeth is caused by deposition of iron in the outer enamel. This deposition may increase the teeth’s resistance to wear, an obvious advantage for permanent teeth that do not continue to grow in response to wear. Shrew feces are often corkscrew-shaped, and some shrews (for example, the desert shrew [Notiosorex crawfordi]) use regular defecation stations. Albino shrews occur occasionally.

Shrews may appear similar to mice. Mice have four toes on their front feet, and… look like “mice”. There are many animals we call mice: house mice, deer and white-footed mice, meadow voles, jumping mice, and many more. The links below will help with your identifications.

Resources: (online)

House mice

Deer mice

Meadow mice