Detroit stands about 597 feet above sea level on the Detroit River, the strait that joins Lake St. Clair to Lake Erie. Older housing, cold winters and humid summers shape which pests move indoors.
Detroit sits on the Detroit River, across from Windsor, Ontario. Antoine de la Mothe Cadillac founded the settlement in 1701, and Wayne County's seat counted 639,111 residents in the 2020 census. Wikipedia says the city keeps one of the largest surviving collections of late 19th and early 20th century buildings, a stock that runs from Corktown to Boston-Edison.
Buildings of that age have plenty of seams at foundations, porches and rooflines for small pests to use. A 2009 parcel survey found about a quarter of residential lots vacant or undeveloped, so conditions change a great deal from block to block. The January mean is near 26 degrees and July averages about 74, which gives some pest a reason to come inside in every season.