Rats and mice are among the most common household pests, but knowing which one you’re dealing with is essential for effective control. Although they’re both rodents, rats and mice differ significantly in size, behavior, and signs left behind.
This quick guide from Nature and Wildlife Solutions explains how to tell the difference between rats and mice.
1. Size and Appearance
Rats:
- Larger and bulkier, measuring 9–11 inches long (excluding tail)
- Thick, scaly tail usually shorter than their body
- Blunt nose and a larger head compared to body size
Mice:
- Small and slender, only 2–4 inches long (excluding tail)
- Thin, hairy tail usually as long or longer than their body
- Pointed nose and a smaller head relative to their body
2. Ears and Head Shape
Rats:
- Smaller ears in proportion to their head
- Blunt snout
Mice:
- Larger ears relative to their head
- Pointed snout
3. Behavior and Lifespan
Rats:
- More cautious and less likely to explore new environments
- Lifespan: 2–3 years
Mice:
- Highly curious and more exploratory
- Lifespan: 1–2 years
4. Droppings and Signs
Rats:
- Droppings are larger (about ¾ inch), shaped like pellets
- More likely to burrow or nest in walls, basements, and sewers
Mice:
- Droppings are smaller (about ¼ inch), grain-like
- Tend to nest indoors in hidden places close to food sources
5. Diet and Habitat
Rats:
- Omnivorous: will eat a varied diet including grains, fruits, and even meat
- Commonly found outdoors or in basements and sewers
Mice:
- Mostly herbivores: prefer seeds, grains, and plant-based food
- More likely to live indoors near food sources
Summary Comparison Table
| Feature | Rat | Mouse |
|---|---|---|
| Size | 9–11 in (body length) | 2–4 in (body length) |
| Tail | Thick, scaly, shorter than body | Thin, hairy, as long or longer than body |
| Head & Nose | Blunt nose, larger head | Pointed nose, smaller head |
| Ears | Small relative to head | Large relative to head |
| Behavior | Cautious | Curious and exploratory |
| Lifespan | 2–3 years | 1–2 years |
| Droppings | Large, ¾-inch pellets | Small, ¼-inch grain-like |
| Habitat | Burrows, basements, sewers | Indoors near food sources |
| Diet | Omnivores (eat varied diets) | Mostly herbivores (seeds, grains) |