In bad cases, after about 3 days, it starts to look like a cockroach armageddon with dying roaches twitching as they come out of the cracks to die.Tenant cleanliness, like keeping up with the trash and not leaving water and food out, is paramount in preventing/controlling infestations.

The big three expenses of the American household are housing, transportation, and food.

Of rotten wood is kept, it will be a great food source for termites, which you don’t want obviously

How about for food?

Now will I mention the crime, drugs, unemployment, welfare, riff raff and general misery that is prevalent.Refineries, industrial plants, power plants, military bases, food processing facilities, shipyards, factories, distribution centers, university, etc. 

The senior uses her Social Security money and her children uses their income to mostly pay the utilities and food.  

There was one sushi place (now defunct) where the chances of food poisoning were 50/50, a Mexican place with slightly better odds (also defunct), Gunbarrel Deli back when it was owned by nazis, the King Soopers, and that's literally it.

-Rents have increased since 2015-SNAP/Food Stamps percentage down since 2015-Percent poverty has decreased since 2015-Percent college educated has increased since 2015Is this one of those times you're supposed to keep quiet so other people don't start to find out this might be a good place to invest?

You can get paid $20-30/hr in most areas for anything from cleaning to tutoring to pet/baby sitting to food delivery.

The overall character of the area is definitely a large factor as it will determine the type of tenants living there/demographics: Yoga/Orange Theory studios, Whole Foods, Starbucks, micro breweries, wine and cheese shops, public parks, bike paths, green spaces, public transportation, good schools, nice restaurants, cranes/new construction, low crime rate, high prices all indicate a Class A area whereas boarded up buildings, lots of Payday lenders/check cashing stores, dollar stores, fast food, liquor stores, homeless shelters, army recruiting centers, addiction recovery centers, industrial areas, dumps, shoes hanging from power lines, junked cars lining the streets, high crime, blight, abandoned buildings, urban decay, burnt out buildings, low prices, low rent, etc. would indicate a Class D area.It's really pretty subjective though, I'm not sure there are universally accepted definitions but rather just people's opinions.