🐭 Rodents

House mouse

Mus musculus

Rice-sized droppings, and a gap the width of a pencil is enough.

Size
Body two and a half to four inches, with a tail about as long again
Colour
Dusty grey to light brown, paler underneath
Risk
Moderate
When
Indoor activity rises sharply from the first cold snap in autumn
A house mouse in profile: a small grey-brown rodent with large ears, prominent eyes and a pointed snout.
Large ears and a pointed snout on a small body. Compare the head against a rat's before deciding. AI-generated illustration · FreePestControlInspection.com

How to identify it

Work down these in order — the first one is usually enough on its own.

  • Small head relative to body, with large ears and prominent eyes
  • Pointed snout
  • Droppings roughly the size of a grain of rice with pointed ends

What it gets mistaken for

Most people arrive at a pest name by ruling things out. These are the ones that genuinely look similar, and the detail that separates them.

Where you will find it

  • Kitchen cabinets, pantries and behind appliances
  • Wall voids and the space under base units
  • Attics, garages and storage boxes
  • Anywhere within about thirty feet of a food source

Signs it is already there

You will nearly always see the evidence before you see the pest itself.

  • Small pointed droppings clustered along walls and in drawers
  • Gnawed food packaging
  • Shredded paper or fabric gathered into a nest
  • Light, fast scurrying sounds at night

Moderate. Worth dealing with, but not an emergency.

Why it is harder to deal with than it looks

Mice can pass through a gap around a quarter of an inch, and they breed quickly. Trapping alone removes the animals currently inside but leaves the opening they used, which is why some households trap every single year.

What actually works

Exclusion. Seal every gap with copper mesh, stainless wool or hardware cloth — expanding foam alone gets chewed straight through. Trap alongside sealing, and remove the food and water that made the space worth occupying.

Common questions

How do I tell a house mouse from a roof rat?

Roof rat droppings are more than twice the size, and a roof rat is obviously larger with a tail longer than its body.

How do I tell a house mouse from a norway rat?

Norway rats are much heavier with a blunt nose and a tail shorter than the body.

Where are house mouse usually found in a home?s

Kitchen cabinets, pantries and behind appliances Wall voids and the space under base units Attics, garages and storage boxes.

Is a house mouse dangerous?

Contaminate food and surfaces, and gnaw wiring. Droppings and urine can carry pathogens that become airborne when disturbed, so dry sweeping is not advisable.

Identification guidance only. Under Texas law, applying pest control treatments for hire requires a licence from the Texas Department of Agriculture. This page describes what a pest looks like — it is not a diagnosis of your property or a treatment recommendation for it.