Land crabs is a great comparison as far as used cars are concerned. We liken them to termites though because when they move into an area it generally does not seem to take long before everything is destroyed.
I notice that on heavy haul days they will comb my ‘hood and grab anything that is not overtly busted, before the city truck comes.
How lucrative can it be, driving around for miles picking up random bits of metal?
I guess you gotta factor in all the theft they perpetrate. They grab stuff opportunistically as they drive through, and also make a mental note and come back later. That happened to my next door neighbor.