Pest Control in Warren, Michigan

A factory town before it was a suburb

Warren’s adopted Master Plan puts it plainly: the city was an industrial hub before it was a residential suburb. The Detroit Arsenal Tank Plant began mass-producing tanks in 1941 and kept building them until 1997. General Motors started construction on its Technical Center in 1949, and the first phase was finished in 1956. Warren officially became a city on October 27, 1956, and its population doubled between 1960 and 1970 before peaking that year.

The Tech Center itself is a National Historic Landmark. The state historic preservation office credits the campus as one of Eero Saarinen’s most important works and lists its designations: National Register of Historic Places in 2000, a Michigan Historical Marker in 2002 and National Historic Landmark status in 2014. The city describes it as a 710-acre campus with 11 miles of roads, two water towers, two lakes and a network of tunnels, and calls it a tipping point for the development of the rest of Warren.

For anyone dealing with pests, the history explains the housing. Tens of thousands of homes were built in a short window for plant and office workers, on similar lot sizes and with similar construction methods. Those houses have now aged together, and they tend to develop the same weak spots at about the same time.

What the Census says about Warren’s post-war homes

The 2020 Census counted 139,387 residents in Warren. American Community Survey estimates for 2019–2023 show about 57,700 housing units, and the age profile is unusually concentrated. The 1960s alone account for 36.7 percent of units and the 1950s for another 21.7 percent, so roughly 58 percent of the city’s homes were built in those two decades. Counting the 1940s and earlier, about two-thirds of Warren’s housing (67.5 percent) was built before 1970, while only about 2.4 percent has been built since 2010.

Three out of four units (75.6 percent) are detached single-family houses, and 71 percent of occupied homes are owner-occupied, leaving 29 percent rented. In practical terms that means a city of small brick and frame ranches and bungalows, many with basements, where the common entry points are cracked mortar at the foundation, worn door sweeps, gaps where utility lines enter, and basement windows set close to grade.

Basements, footing drains and the Red Run

Moisture is the thread that ties many Warren pest calls together. According to the Master Plan, most of Warren’s development happened between the 1950s and the 1970s, and an estimated 45,000 to 49,000 homes have footing drains connected to the sanitary sewer. In heavy rain, that extra clean water can overload the sanitary system and lead to basement overflows. The city has studied disconnection and installed several new relief sewers, but the underlying design is still common across older neighborhoods.

The whole city sits inside the Red Run subwatershed, so rain that falls anywhere in Warren eventually drains toward the Red Run. The Master Plan notes that the city’s only mapped floodplains surround the Red Run Drain and its tributaries in north Warren, and it lists Bear Creek Drain among the local waterways. Damp basements, wet sill plates and leaking floor drains draw moisture-loving insects such as centipedes, silverfish and carpenter ants. A licensed company inspecting a Warren basement should be looking at drains and water sources, not only at the pests themselves.

Rental licensing and who fixes what

Nearly three in ten Warren households rent, and every rental is supposed to be licensed. No one may rent or occupy a rental dwelling without a license from the Rental Inspections Division. The city’s renewal checklist has the owner schedule an inspection within 30 days of applying; a passed inspection keeps the license valid for two years. After a failed inspection the owner gets a set window to finish the work and pass a second inspection, and a failed third inspection brings a ticket for every day out of compliance. Houses left empty or under renovation for more than 30 days must be registered as vacant under Section 28-64 of the city code. The Rental Inspections Division, on the third floor of City Hall at One City Square, can be reached at 586-574-4633.

Bed bugs are the pest where landlord and tenant cooperation matters most. MSU Extension points out that Michigan law expects landlords to make a good-faith effort to provide housing free of bed bugs, and it advises property managers to arrange an inspection as soon as they are told of a problem, with confirmation by a pest management professional. Adjacent units above, below, beside and across the hall should be inspected, and every affected unit treated at the same time. MSU also recommends written preparation instructions for the tenant and careful records on both sides. The state’s Michigan Manual for the Prevention and Control of Bed Bugs includes a sample treatment agreement.

Rubbish, garbage carts and rats

Warren’s website sends “rat problem” reports to the Property Maintenance Division, which runs the city’s blight hotline at 586-574-4662. The rules that division enforces are the ones that decide whether rats have anything to eat. In March 2025 the City Council adopted Ordinance 80-830, rewriting the noxious weeds and rubbish article of Chapter 21. It bars owners, operators and occupants from letting rubbish accumulate, and its definition of rubbish expressly includes food waste. For rubbish, the city must give at least ten days’ notice before cleaning a property itself and billing the owner; for overgrowth, which the ordinance defines as grass over six inches, the notice period is 24 hours. Chapter 28 of the code adopts the International Property Maintenance Code.

The Sanitation Division’s curbside rules add a daily-habits layer. All garbage must go in the city-issued 95-gallon blue cart or in plastic bags; paper bags, bushel baskets and filled boxes are not collected. Refuse is stored in the rear yard until 6:00 p.m. the evening before pickup and must be at the curb by 6:00 a.m. on collection day. Keeping lids closed and bags inside the cart, rather than stacked beside it, removes much of what attracts rats to alleys and garages.

Inside the house, mice are the more common problem. MSU Extension’s advice is to seal any gap to the outside wider than a quarter inch, and to use mortar, sheet metal or heavy hardware cloth rather than spray foam, which mice can chew through. It recommends setting six or more traps along walls where mice travel and advises against poison bait indoors, since mice may die inside walls and cause odor problems. Its warning on numbers is worth remembering: a female mouse can produce five to ten litters a year.

What the Macomb County Health Department does and does not do

Warren residents often expect the county health department to force a landlord or neighbor to deal with pests. Its own Healthy Homes page says otherwise: Environmental Health staff offer guidance and education on housing conditions, including cockroaches and bed bugs, but the department states that it has no authority over private homes, rental properties included, and may not be able to make an owner fix a problem. For rentals in Warren, the city’s rental inspection program is the enforcement route.

Where the county does act is surveillance and food safety. The Health Department describes West Nile virus as endemic in Macomb County, tests mosquito pools through spring and summer, and notes that crows and blue jays are especially affected; sick or dead birds can be reported to the Michigan DNR. It has monitored for blacklegged (deer) ticks since 2018, reports established populations in the county, and says ticks collected in Macomb County in 2021 tested positive for the bacterium that causes Lyme disease, with transmission most likely from April through September. It inspects licensed restaurants and takes complaints about unsanitary conditions in food service. Environmental Health can be reached at 586-469-5236.

A private yard program for mosquitoes or ticks is private work and is handled by a licensed company, not the county.

Wildlife and older homes

Raccoons, skunks and opossums are a separate matter from insects and rodents. Warren Animal Control, at 586-574-4806, handles stray and lost animals and notes that animals it recovers are taken to a shelter in Mount Clemens. For a raccoon in the attic or a skunk under a porch, the owner generally hires a private company to remove the animal and seal the opening. Owners of homes built before 1978 should also know about the city’s Lead Hazard Control and Healthy Homes Program, since sealing entry points in an older house often means scraping or cutting painted trim; income-eligible owners and some landlords may qualify for help making those homes lead-safe.

ZIP codes served

Checking a Warren exterminator’s Michigan credentials

Any company applying pesticides for hire in Michigan must hold an MDARD Pesticide Application Business License, and the people doing the work need their own commercial certification or registration. MDARD says those individual credentials expire every third year on December 31, and the expiration date is printed in the lower right corner of the card. The categories matter: 7A is General Pest Management, 7B is Wood Destroying Pest Management, 7D is Vertebrate Pest Management for rats, mice and birds, and 7F is Mosquito Management. MDARD also offers a combined Category 7J that covers both 7A and 7B. Before the first visit to a Warren home or rental, ask for the business license number and the technician’s category card.