Drug houses don't just happen in other neighborhoods. There are drug houses in all types of neighborhoods. Most neighborhoods have very little control over Product, Buyer or Seller. Drug dealers look for locations where neighbors do not communicate and isolate themselves. This makes it easy to intimidate those neighbors that do notice drug activity.
Money is the key element for the drug dealer.
If they establish a drug house where kids and adults have money to buy drugs, business will thrive. Excessive foot traffic to and from a house or property. Loitering in or around a house. Frequent and unusual traffic patterns-Stop, Enter, and Leave. Traffic frequently stops and a resident comes out and talks briefly with occupants of car.