How to Distinguish House Mice from Deer Mice
Deer mice apparently can carry the hantavirus and Lyme disease vector, but house mice don't. First, is that true? And second, I caught two of the mice in my house with snap traps and am trying to figure out whether they are house mice or deer mice. How can homeowners tell the difference? And are there reliable resources, with photos showing the differences, and describing the differences that you can help me access? Sorry, I don't have a photo, as already disposed of them.
Montgomery County Maryland
It is the uncommon home that doesn't eventually deal with mice at some period of time, and according to the CDC, Hanta virus is very rare here.
We would not be overly concerned with specific identification, but recommend snap trapping as you have done, and tightening up (caulk, extruding foam, replacement or repair of door sweeps/window screens) around where utilities/pipes/wires enter the home.
Here is our page on Mice: https://extension.umd.edu/hgic/topics/mice'
and here is one from Penn State: https://extension.psu.edu/is-there-a-mouse-in-the-house
We are not experts on i.d. but this publication tells you more:
"All of the Peromyscus species have white feet, usually white undersides, and brownish upper surfaces. Their tails are relatively long, sometimes as long as the head and body. The deer mouse and some other species have a distinct separation between the brownish back and white belly. Their tails are also sharply bicolored. It is difficult even for an expert to tell all of the species apart."
Keep in mind that these are native rodents that are part of the natural web of life outdoors.