San Francisco Environment Department

Eeek! I've got mice - what should I do?

Remove sources of food, water, and shelter.

Clean up potential food sources such as trash, fallen fruit from fruit trees, or pet food. Consider cutting back excessive vegetation growing on or near your building, as this provides shelter for rodents and encourages their presence. For example, ivy provides a perfect habitat for mice and rats.

Seal out rodents.

Mice can fit through gaps as thin as a pencil. Seal up gaps of that size or larger with 1/4" screening, escutcheon plates, and or metal wool (copper or stainless steel). Purchase a door sweep to seal large openings under doors.

If rodents persist, use snap traps.

Use traditional snap traps if you still have a problem. Use lots of them; at night, place them on rodent trails (along the edges of walls and corners), and pre-bait (placing traps down without setting them) for the first day. Remember to keep pets and children away from trap-laid areas.

Related Content

Pest Management for Residents

Additional Resources

Rats and Mice Factsheet (Our Water, Our World)
National Pesticide Information Center: Rats
National Pesticide Information Center: Mice
National Pesticide Information Center: Rodenticides
National Center for Healthy Housing: Rodents and Health


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