Most of what protects a household from plague is ordinary housekeeping done on purpose. It matters where plague exists in wild animals; elsewhere it is simply good practice against rodents.
A home that rodents do not want.
- Keep food in containers a rat cannot open: glass, metal, or bins with tight lids.
- Leave no food waste out. Sweep floors and tables; keep kitchen refuse in a bin with a tight-fitting lid.
- Do not leave pet food or bird seed where rodents can reach it.
- Cover water containers.
- Find the holes and close them — in walls and floors, under doors, around pipes and cables — with mortar, concrete, metal sheet or wire mesh.
- Outside: clear brush, rock piles and junk, and stack firewood away from the house.
Pets.
- Use a flea-control product on cats and dogs. Ask a veterinarian which one.
- Where plague exists in wild animals, do not let pets roam and hunt. They bring fleas home, and cats catch plague themselves.
- A pet that roams does not sleep on your bed.
- A sick cat — fever, no appetite, no energy, sometimes a swelling under the jaw — goes to a veterinarian promptly. Say what you suspect before you arrive. Handle the animal as little as you can, and keep your face away from it.
Outdoors: hunting, hiking, field work.
- Repellent, long trousers, closed shoes.
- Do not handle sick or dead animals. Gloves for skinning and butchering.
- Do not camp or rest beside rodent burrows and nests.
- A colony of ground rodents that has suddenly fallen silent is a warning. Leave, and report it.
Travel.
- Before. Read the travel-health advice of your own country for the place you are going to. For an ordinary traveller the risk of plague is very low.
- There. Use repellent. Avoid dead animals. If pneumonic plague has been reported, avoid crowded places and anyone who is coughing.
- After. If you develop a fever within 10 days of coming back, see a doctor at once and say where you have been.
What a household does not need.
- A stock of antibiotics "in reserve". Taking them without a prescription is the mistake, not the precaution.
- Rodent poison laid during a die-off of rodents. It sends their fleas looking for you.
- Disinfecting the whole house. The bacterium does not persist on dry surfaces; what needs dealing with is fleas, and anything soiled with pus or sputum.
Source. United States Centers for Disease Control and Prevention, Preventing plague, https://www.cdc.gov/plague/prevention/index.html ; WHO, Manual for plague surveillance, diagnosis, prevention and control (2024), Annex 12, https://www.who.int/publications/i/item/9789240090422 ; UK Health Security Agency, Plague: epidemiology, outbreaks and guidance, https://www.gov.uk/guidance/plague-epidemiology-outbreaks-and-guidance
What this is not. Reading, not pest-control or veterinary advice. Insecticides and rodenticides are used according to their labels and the rules of the country you are in.