Teardown Rats, Flooded Basements and River Wildlife from Hamlin Park to Montrose

A township line on Western Avenue and an amusement park by the river

Western Avenue once divided two townships. The land east of it belonged to Lake View, the land west of it to Jefferson, and both were annexed to Chicago in 1889. Before that, this was farm country with clay along the North Branch suited to brickmaking. Two arrivals turned it residential. Streetcars came up Lincoln Avenue, and in 1907 the Ravenswood elevated line, today's Brown Line, opened along the eastern edge. Riverview Park, a 76-acre amusement park, ran from 1904 to 1967 near Western and Belmont, drawing crowds to the river's edge for more than six decades.

By the 1920s the grid was largely built out. Roscoe Village kept many of its older frame cottages and Queen Anne houses, since Lake View lay outside the city's post-1871 fire limits when they went up. The rest filled with brick bungalows with full basements, two-flats with wood rear porches, and detached alley garages. Since the 1990s, though, demolition has become the neighborhood's defining rhythm. On a typical block, a 1915 bungalow now stands between two houses built in the last fifteen years, and that churn of teardowns and deep excavations drives more pest calls than any single animal.

Teardown blocks and the displaced Norway rat

Norway rats live in burrow systems under garages, porches, sheds and overgrown yards, and a colony can occupy the same lot for years. When an old house and garage come down, those burrows are crushed or exposed, and the rats that survive scatter to the nearest shelter. On narrow lots that means the yards, garages and basements on either side and across the alley. Excavation for a new basement also cuts and caps old sewer laterals, and a damaged lateral can let rats move through pipes and up into a neighbor's floor drain.

Neighbors usually notice within days: fresh burrows along a shared fence, gnawed cart lids, droppings in the garage, scratching in a wall. Rats avoid unfamiliar objects for several days, so traps set the first night often sit untouched, and a homeowner concludes nothing is there. North Center even had a public reminder of how ordinary rats are here. An animal-shaped imprint in a Roscoe Street sidewalk, popularly called the Chicago rat hole, drew crowds until the city removed the slab in April 2024.

The best response starts before the excavator arrives. If a house on your block has a demolition permit, ask whether the site was baited first, and have your own property protected: tamper-resistant stations along the shared fence and garage, a heavy threshold seal under the garage door, hardware cloth over window wells and a check of the basement floor drain. Providers who work here often set stations on adjoining lots in the first weeks of construction and keep monitoring until the new foundation is poured and backfilled. City crews bait public alleys after a 311 request, but private yards are the owner's job.

Storm backups and the millipede flush

Heavy rain is the second pest driver. Older bungalows and two-flats tie into combined sewers through aging laterals and drain tile, and intense storms can push water back up through basement floor drains. The April 2013 storms that sent the North Branch over its banks upstream in Albany Park also flooded basements across this part of the North Side. Many owners have since added backflow valves, overhead sewers or sump pumps, and the city encourages disconnecting downspouts where it is allowed.

Water changes the pest picture fast. Millipedes, sow bugs, house centipedes and silverfish thrive in damp basements and often appear by the dozen after a storm or a wet spring. House mice move into finished basements when floods soak their outdoor shelters, and wet cardboard storage gives them ready nesting material. Drying the space quickly, discarding soaked boxes and running a dehumidifier come first. Sealing cracks at the floor-wall joint and a perimeter treatment keep invaders from returning once the basement is dry. Check window wells as well: a well that fills with leaves and water acts as a funnel for millipedes and a ramp for mice.

House mice in bungalow basements and two-flat laundry rooms

Rats get the attention, but house mice are just as constant, and their season is predictable. From September into November, as nights drop toward freezing, mice probe every bungalow and two-flat foundation on the block. They need an opening about the width of a pencil, and century-old brick offers plenty: sunken mortar joints at grade, the outline of a bricked-over coal chute, the gap around a gas service line, a basement window frame that has pulled away from the masonry. Two-flats add a shared laundry room and storage areas full of cardboard, where a colony can grow unnoticed before anyone upstairs hears scratching.

Bungalows with finished basements hide the problem longer, because paneling and drywall cover the original walls and give mice a sheltered runway to the kitchen above. The fix is the same in both: a provider maps droppings and rub marks, traps or baits inside, then closes the foundation gaps with mortar, copper mesh or sheet metal and fits sweeps on basement and rear doors. Without the sealing, a new wave arrives the following fall.

Raccoons, skunks and carpenter ants along the river side

The western edge follows the North Branch, a green corridor of trees and banks connecting Clark Park, Revere Park and the river's edge in Hamlin Park. Raccoons, Virginia opossums, striped skunks and the occasional coyote travel it, and the blocks closest to the water see the most wildlife. Raccoons climb garage roofs and rear porches to reach attics; skunks dig under decks, porches and concrete stoops, especially in spring when they need dens for their young. Illinois regulates trapping and relocation, so licensed specialists handle it, usually with a one-way door followed by heavy mesh buried below grade.

Frame houses bring a different problem. In Roscoe Village and on scattered older blocks elsewhere, wood sills sit a few inches above soil, porches have been rebuilt many times and additions meet original framing at joints that trap water. Black carpenter ants, among the largest ants in northern Illinois, excavate that damp wood for nests. Winged ants indoors in late winter, coarse sawdust below a window frame or porch beam, and large black workers in a spring kitchen point to a colony inside the structure. Eastern subterranean termites are less common here but do occur where wood touches soil, and the two need different treatments.

Bungalow, two-flat, frame cottage, new build: where each one leaks

A 1910s or 1920s brick bungalow tends to fail at the foundation and the roofline. Look for open mortar joints, an old coal chute opening, cracked glass block windows and gaps around gas and water lines. The half-story attic often has soffit and gable vents squirrels can open. A two-flat adds a wood rear porch stack and a shared basement laundry, and its detached garage with a cracked slab or dirt floor is prime rat territory.

Frame cottages need moisture control first: clearance between soil and siding, working gutters and sound porch beams. A new build has tighter brick and siding but its own weak points. Deep window wells collect water, utility penetrations for air conditioning lines, dryer vents and gas meters are often left unsealed, thick mulch beds against the foundation shelter ants and rats, and attached garages offer a straight route indoors when the door seal fails. Every house type here benefits from a yearly perimeter walk. The detached garage deserves its own look on any lot: a gap of half an inch under the overhead door, a rotted jamb or a slab that has heaved and cracked is enough for a rat, and garages full of stored boxes, birdseed and pet food become the base camp from which rats reach the house.

North Center by the season

Spring, March through May: snowmelt and storms raise flood risk and bring millipedes and centipedes indoors. Construction season starts in earnest, and with it a fresh wave of displaced rats on teardown blocks. Skunks and raccoons choose dens, squirrels give birth in attics, and carpenter ant swarms appear inside frame houses. Any roofline repair has to be timed so young animals are not sealed in.

Summer, June through August: rats are most active outdoors, odorous house ants trail into kitchens after rain and wasps build under eaves and porch ceilings. Each heavy storm is a reason to check the basement again. Fall, September through November: house mice push indoors, squirrels test attics for winter and their second litters leave the nest. Winter, December through February: rodents already inside stay active near heat, and it is the right time to plan exclusion work, waterproofing and any carpentry before spring. Tracks in fresh snow along fences and garage doors also show exactly where rats are traveling, which helps a provider place stations before the spring construction wave.

Checklist for a block in transition

These steps target what stands out in North Center: nearby demolition, flood-prone basements and the river corridor. Most fit into a weekend or a yearly maintenance routine, and they work best when neighbors on the same alley do the same. If time is short, start with the garage and the basement, where rats and mice most often get established on these lots.

• When a teardown is scheduled nearby, have your yard and garage inspected and protected before demolition starts
• Seal gaps under garage doors and around utility lines entering the house
• Cover window wells and basement vents with hardware cloth or fitted covers
• Install or test a backflow valve or sump pump, and disconnect downspouts where permitted
• Dry and clear the basement quickly after any water intrusion and discard wet cardboard
• Keep mulch thin near foundations and at least six inches of clearance below wood siding
• Secure compost, birdseed and pet food, especially on blocks near the river
• Report alley burrows and damaged carts through 311

Construction neighbors, alley garages and the written entry-point report

A first visit generally covers the exterior, garage and alley, the basement and any crawlspace, and the attic when wildlife is suspected. If construction is underway next door, the provider concentrates on the shared property line and places stations along it. Rat programs typically include several follow-up visits to check stations, reopened burrows and the garage. Carpenter ant inspections add a moisture meter and a close look at sills, porch beams and the joints where additions meet the original house.

For two-flats with a rental unit, the owner usually arranges access; in converted condo buildings the association approves exterior station placement. Exclusion work such as sealing foundation gaps or burying mesh around a deck may happen on the same visit or be scheduled separately. Same-day service is often available when a provider's calendar has room. Ask for a written summary of entry points and recommended work, which is useful to share with a neighbor, a builder working next door or an insurance adjuster after a flood.