Although other species are still used in specialist labs, mice are by far the most commonly used mammal in medical and other scientific research. Mice have been used in scientific research since the 1600s. They have been experimented on for many disease testings, the development of important new drugs, etc. But why is this animal experimented on the most? Mice are considered very similar to humans, overall, they share virtually the same set of genes, also, some sophisticated emotional characteristics, and they are highly communicative. Even though they have similarities they differ in size, and the fact that humans use them as experiments, being humans a big threat to them.

Genetically mice and humans are very similar. Both the mouse and human genomes contain about 3.1 billion base pairs. This similarity makes mouse genetic research particularly useful for the study of human diseases. Now scientists use mice to simulate human genetic disorders in order to study their development and test new therapies. Mark A. Suckow, D.V.M. Peggy Danneman, V.M.D. Cory Brayton, D.V.M., A Volume in The Laboratory Animal Pocket Reference Series: The Laboratory Mouse “They are also used in a variety of other types of research, including cancer, immunology, toxicology, metabolism, developmental biology, diabetes, obesity, aging, and cardiovascular research, because of the genetic and biological similarities.”

Mice have a way of expressing their feelings. It's now thought mice can be affected by another mouse's pain or suffering, therefor, mice show emotion. According to Dr. Jeffrey Mogil, professor of Pain Studies, McGill University, Montreal, in Research Shows Mice May Have Feelings, Too: “It appeared that the order in which you tested mice for pain from a cage of mice had an effect on their pain sensitivity.” In the research, they injected a substance that can cause a mild stomachache. It showed that if a mouse sees another in pain, they express empathy. They, also, concluded they can empathize with the other species that are not even like them.

Mice and humans have a way of communicating. Even though they are different, they are effective. Mice have facial expressions. These facial expressions show their moods to other mice. They are intelligent creatures with complex levels of communication: vocal – often beyond the auditory range of humans and body language. Some mice will be keep-fit fanatics, running on wheels and chasing around, while others will be homemakers, building comfortable nests. Some are playful while others are shy. Humans, as well, have many personalities this is what makes us all unique.

Even though mice are very similar to humans in communication, genetics, and emotional expression, we differ in many ways like in eating preferences, mice are herbivores and humans are omnivores. We differ in size, as well, because of their size they are easily manipulated and seem as a non-threat to humans, and this is why humans experiment on mice easily. The news article Of mice and medicine: the ethics of animal research establishes that every day, about 25 million mice are used globally in research into and development of treatments for diseases including malaria, heart disease, cancer, and Aids. Humans need to know about the ethics of animal testing and look for a better way to respect these animals that are very similar to us.