Yes, rats do appear on cruise ships, though the industry works hard to prevent infestations

Rats board cruise ships the same way they board cargo vessels and commercial buildings: they stow away in supplies, slip through open doors during port calls, or hide in cargo containers before they're loaded. Once aboard, they find food in galleys, pantries, and passenger areas, plus plenty of dark spaces to nest in engine rooms and wall cavities. The difference between a cruise ship and a land building is scale—a large cruise ship can carry 5,000 or more people plus crew, which means more food waste, more places to hide, and more difficulty spotting an infestation before it spreads.

The cruise industry is regulated by the U.S. Public Health Service (for ships calling at U.S. ports) and by international maritime health standards. These inspections focus on sanitation, pest control, and food safety. Ships that fail inspections must correct violations before they sail again. That said, inspections happen on a schedule, not continuously, so a rat problem can develop between inspections if prevention measures fail.

Key Takeaways

  • Rats reach cruise ships through cargo, supplies, and open gangways during port calls, not because of poor ship design.
  • The U.S. Public Health Service inspects cruise ships for pest control and sanitation violations before they sail from U.S. ports.
  • Crew members are trained to spot signs of rodents and report them to the ship's environmental health officer.
  • If you see evidence of rats during your cruise, report it to guest services or the front desk when ready so the ship can document and address it.
  • Keeping your cabin clean and storing food in sealed containers reduces the chance you'll encounter rodents in your personal space.

How rats get aboard and where they hide

Rats typically board during port calls when cargo is loaded, supplies are brought aboard, or the gangway is open for extended periods. A rat can slip through a gap the size of a dime, so even small openings are enough. Once inside, they move through wall cavities, ventilation ducts, and the spaces behind paneling—areas passengers never see. They're most active at night and in areas with the least human traffic, which is why engine rooms, storage holds, and crew quarters are common hiding spots.

Food waste from the galley is the main attraction. Cruise ships generate enormous amounts of food scraps, and if waste isn't sealed and disposed of quickly, rats will find it. They also gnaw through packaging to reach dry goods stored in pantries. A single rat can contaminate far more food than it eats by leaving droppings and urine, which is why even a small infestation is taken seriously.

What cruise lines do to prevent and control rodents

Cruise lines employ several layers of pest prevention. Ships have designated pest control officers who inspect the vessel regularly, set traps in high-risk areas, and monitor for signs of activity. Food storage areas are sealed and climate-controlled, and waste is stored in sealed containers until it's disposed of at port. Crew members are trained to spot droppings, gnaw marks, or other evidence of rodents and report them when ready.

Before a ship departs from a U.S. port, it undergoes a Public Health Service inspection that includes checking for evidence of pests. The inspector looks for droppings, gnaw marks, dead rodents, and signs of infestation in food storage, galleys, and crew areas. If violations are found, the ship must correct them before it can sail. Ships calling at international ports are also subject to local health authority inspections, which vary by country but follow similar standards.

Public Health Service inspections and what they cover

The Centers for Disease Control and Prevention (CDC) operates the Vessel Sanitation Program, which inspects cruise ships that carry 13 or more passengers and call at U.S. ports. Inspectors board unannounced and conduct a thorough walk-through of food storage, galleys, dining areas, crew quarters, and other spaces where pests might hide or contaminate food. They look for live rodents, droppings, gnaw marks, and conditions that would allow pests to enter or thrive.

Inspection scores are public and available on the CDC website. A ship that scores below 86 out of 100 is considered to have failed and cannot sail until violations are corrected. Even ships that pass can have minor violations noted, which the cruise line must address by the next inspection. Inspections typically happen every six months, though the CDC can inspect more frequently if there's a history of problems.

Signs of rodents you might notice as a passenger

Most passengers never see a rat because they're nocturnal and avoid people. However, you might notice droppings (small, dark pellets about the size of a grain of rice), gnaw marks on packaging or wood, or a musty smell in certain areas. You might also hear scratching or squeaking in walls, particularly at night. Some passengers report seeing rats in crew areas or storage spaces, though this is uncommon on well-maintained ships.

If you see evidence of rodents in your cabin or in a public area, report it to guest services or the front desk when ready. Document what you saw (take a photo if possible) and note the location and time. The ship is required to investigate and take corrective action. Your report also creates a record that helps the crew identify whether there's a larger problem that needs attention.

What to do if you encounter a rat during your cruise

If you see a live rat or significant evidence of rodents, stay calm and move away from the area. Do not attempt to trap or handle the animal yourself. Go directly to guest services or the front desk and describe what you saw, including the location and time. Provide as much detail as you can—whether it was in your cabin, a corridor, a dining area, or elsewhere.

The ship's crew will investigate and take steps to address the problem. Depending on the severity and location, this might include setting traps, sealing entry points, or deep-cleaning the affected area. If the infestation is severe enough to pose a health risk, the ship may divert to a port for professional pest control treatment. You have the right to request a cabin change if you're uncomfortable staying in your current location, and most cruise lines will accommodate this request without penalty.

Protecting yourself and your belongings in your cabin

Keep your cabin clean and don't leave food or crumbs on surfaces or the floor. Store any snacks or food you bring aboard in sealed containers or the cabin refrigerator. Rats are attracted to open food sources, so even a few crumbs can draw them in. Keep your cabin door closed at all times, and report any gaps or damage to the door seal to guest services.

Stow your luggage in the closet or under the bed rather than leaving it open on the floor. Rats can nest in soft materials, and an open suitcase is an inviting space. If you notice any signs of rodent activity in your cabin—droppings, gnaw marks, or a musty smell—report it when ready and request a different cabin. Don't wait to see if the problem goes away on its own.

Frequently Asked Questions

How common are rats on cruise ships compared to other ships?

Rats are found on cargo ships, fishing vessels, and commercial shipping at similar rates. Cruise ships may actually have fewer infestations because they're inspected more frequently and have stricter sanitation standards. However, the large number of passengers and crew, plus the constant flow of supplies and cargo, means the risk is always present.

Can rats spread disease on a cruise ship?

Rats can carry diseases including hantavirus, leptospirosis, and salmonella, which they transmit through droppings, urine, or bites. However, the risk to passengers is very low because rats avoid people and because food handling areas are sealed and monitored. The bigger concern is contamination of food supplies, which is why the Public Health Service inspects for rodent evidence in galleys and storage areas.

What should I do if I get sick after seeing a rat on the ship?

Report your illness to the ship's medical center or infirmary. Tell the doctor that you saw evidence of rodents and when. This information helps the medical staff narrow down the cause of your illness and report the incident to health authorities if needed. Keep records of your symptoms and when they started.

Can I get a refund if there are rats on my cruise?

Refund policies vary by cruise line and depend on the severity of the problem and when it was discovered. If you report rodent evidence and the ship doesn't address it adequately, document everything and contact the cruise line's customer service after your voyage. You may be able to file a complaint with the cruise line or with the CDC if you believe the ship violated health standards.

Do all cruise ships get inspected for rats?

Ships carrying 13 or more passengers that call at U.S. ports are inspected by the CDC's Vessel Sanitation Program. Ships that sail only international routes or carry fewer passengers may not be subject to the same inspections, though they're still required to follow maritime health standards set by their flag country and by international law.