Mice usually bite humans only if they are sick or cornered. If humans try to catch or chase mice, sometimes they turn around and bite out of fear in order to defend themselves and escape. Mice that bite humans sometimes have diseases that need to be treated quickly.
According to the Centers for Disease Control and Prevention, viruses like the hantavirus pulmonary syndrome are often spread to humans through bites from the deer mouse, cotton rat, rice rat and white-footed mouse. Despite popular belief, according to ND Health, small rodents such as mice rarely spread rabies to humans through biting. Common times for mice to bite humans include when the mouse gains access to a person’s house. Often a person comes into contact with the mouse by accident when opening a drawer or suddenly entering a room. Mice aren’t aggressive in most cases, and generally they run from people as a first recourse. But if the mouse is startled or thinks that it might be in danger, it often bites people reflexively. This also often happens for children who try to keep mice as pets and handle them excessively. If a child squeezes a mouse in their hand, they can expect the mouse to immediately bite them.