Rodent Control

Rats in Watertown: What You Need to Know


Rats are and have been part of the Massachusetts ecosystem since the area was originally settled in the early 17th century. Rats are commonly found in most urban areas, including Watertown and other neighboring communities due to readily available food sources. Rats can potentially act as a vector for diseases such as E. coli, salmonella, hantavirus, and leptospirosis. However, the risks of humans contracting these diseases from rats is very low, as humans do not have repeated or direct contact with rodents. Always remember to use gloves when handling any materials a rodent may have come in contact with, and wash hands promptly after handling the materials.


Rats are a natural part of the urban environment in Watertown and the surrounding great Boston area communities. Rats have been with us for a long time and will thrive in places where they can find an abundance of food, water, and shelter. We have heard from colleagues in many neighboring communities that they are experiencing a similar uptick in rat sightings. Watertown is not unique in this trend.


The most scientific explanation and plausible cause for the increase in rat sightings is related to the shorter and warmer winters we have had in recent years. Rats are typically less active during the colder parts of the year and are less likely to breed. With warmer winters, they can breed more and have more offspring that will eventually increase the size of the population we see during the summer and fall. Other factors that may increase the rat sightings include construction and lack of natural predators. Vibrations from construction may disrupt rodent habitats below ground. Expanding development and decreasing green spaces have caused natural predators to leave urban environments, natural predators include coyotes, foxes, and birds of prey.


The Health Department has many initiatives in place to curb rodent activity in the community. The Health Department works with other City departments, residents, and business owners to promote better understandings of rat behavior and how to minimize their presence and impact on the community. The Health Officers often survey areas of the community for rodent conditions and provide educational information to the public, business, and construction sites to promote and ensure the best practices in the area of pest management and control. When necessary, the Health Department will treat public ways when there is rodent activity observed on public ways. Demolition projects in the community are required to pretreat for rodents and monitor for rodent presence throughout the project and take appropriate pest control steps as needed. For road construction projects the Department of Public Works treats and monitors for rodent presence throughout the project.


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What to do if you see signs of rats (PDF)

Center for Disease Control and Prevention (CDC): Rodent Information 

Think you may have rats on your property? click here for images of what different kinds of rats look like 

How to Prevent a Rodent Infestation on Your Property:

1. Maintain your property in a sanitary manner

Pet waste: remove all dog and cat feces promptly

Grills: keep clean, remove all food waste when not in use

Trash: keep all trash stored in closed tote barrels

2. Eliminate or reduce rodent accessible food and water sources

Birdseed: keep birdseed under control and in the feeder as much as possible

Water: remove all water sources such as bird baths, standing water in tires

Pet food: do not leave pet food out at night

Compost: keep compost securely covered in rodent proof compost containers

Tree fruit: pick up all fallen fruit

  1. Reduce harborage conditions (shelter conditions)

Vegetation: thin vegetation out and keep grass and shrubbery cut short

Yard waste: maintain property and properly dispose of yard waste in yard waste bags

Building materials: stack building materials, lumber and firewood at least 12 inches above the ground

Wood piles: store wood piles neatly with a 12-inch ground clearance

Cover openings: openings in a house or structure greater than ½ inch in diameter should be covered with concrete, sheet metal or wire mesh

  1. Rodent proof all accessory structures (ex. sheds) and garages using durable materials such as ¼ inch mesh, metal hardware, metal lathe, or sheet metal to eliminate all gaps that are greater than ¼ inch.
  2. Routinely inspect your property for evidence of rodents, including rodent burrows, droppings, and chew or gnaw marks

Rodent burrows: holes in ground 4-6 inches in diameter where rats may be living. Look for burrows under porches, under fences, buildings, homes, and cement slabs surrounding structures. Test whether the burrow is active by filling the hole with dirt and checking to see if it is cleared quickly.

Droppings: Rat can leave 40-50 droppings per day and are larger than mouse dropping – approximately 3/4 inch in diameter

  1. If you live in rental housing and you see signs of rodents, tell your landlord.
  2. Share this information with your neighbors. Rodent problems are a community issue. Working together will help eliminate this problem.

If you think you have rodents on your property, contact a licensed pest control company to assist you.

Report rodent sighting to the Health Department so we can take efforts to control rodents on public property and track rodent activity.