Mice

The house mouse (Mus musculus) is one of the most widespread rodents in the world. With an extraordinary reproductive capacity and the ability to slip through openings as small as 6 mm, it is a persistent pest in homes, businesses, and industries. Unlike rats, mice are small, curious, and travel only short distances, so a colony can settle next to the pantry or behind an appliance without the occupant noticing for weeks.

Identification

• Size: 6 to 10 cm body, plus a 7 to 10 cm tail.
• Weight: between 12 and 30 grams.
• Color: light gray to brown, with a lighter belly.
• Ears: large and rounded in proportion to the body.
• Habitat: indoor spaces near food sources: pantries, drawers, behind furniture and appliances.

Signs of infestation

Because of their size, mice leave smaller traces than rats, but in large numbers. These are the signs to watch for:

• Droppings: small (3 to 6 mm), pointed at the ends, and scattered in large quantities, up to 80 per day per individual.
• Gnaw marks: nibbled food packaging, shredded paper and cardboard, and wiring with tooth marks.
• Nighttime noises: faint scratching and scurrying inside walls, drawers, and false ceilings after dark.
• Nests: wads of shredded paper, fabric, and soft material in hidden corners, rarely used drawers, or behind appliances.
• Ammonia smell: a sharp rodent-urine odor in enclosed spaces points to an active population.

Risks to health and property

Mice contaminate up to ten times more food than they consume, scattering droppings, urine, and hair as they move and gnaw. They can transmit diseases such as salmonellosis, hantavirus, and leptospirosis, and they trigger allergic reactions and worsen asthma through the particles in their droppings and urine.

The property damage is significant too: by gnawing electrical wiring they create a short-circuit and fire risk, and they ruin documents, clothing, insulation, and packaging. In food businesses, their presence compromises safety and can result in health penalties.

How Fucesa controls it

Fucesa applies an Integrated Pest Management (IPM) program tailored to mouse behavior, which is neophilic (drawn to new objects) and confined to short ranges. This lets us combine several tools for fast, lasting control:

• Inspection: we locate nests, runways, and entry points near food sources.
• Multiple traps: several mechanical traps in activity areas for rapid capture, ideal in kitchens and food areas.
• Bait stations: rodenticides in tamper-resistant, locked stations where poison use is safe and necessary.
• Exclusion: sealing any opening larger than 6 mm with steel wool, metal filler, or mesh, their main route of entry.
• Sanitation and monitoring: removing hiding spots and food sources, with follow-up to confirm the infestation does not return.

Prevention

• Seal entry points: close every opening larger than 6 mm; an adult mouse can pass through a gap the width of a pencil.
• Order and cleanliness: remove hiding spots and nesting materials such as cardboard boxes, fabrics, and stacked paper.
• Sanitation: store food in airtight containers, clean up crumbs and spills, and keep trash in closed bins.

When to call a professional

Mice breed from six weeks of age, and a single female can have up to ten litters a year, so a couple of individuals becomes a colony in no time. If household traps catch mice repeatedly, if droppings keep reappearing, or if you hear activity in the walls, it is a sign the population is beyond what household control can handle.

Fucesa has more than 40 years of experience in rodent control and operates in compliance with Mexican standard NOM-256-SSA1-2012 and under a COFEPRIS health license, headquartered in Toluca with coverage in Querétaro. Our certified technicians design an IPM program tailored to the property, using products that are safe for the family when instructions are followed.