North Texas.. I didn't ask about the customer. Probably a house in an HOA. Such areas usually have plenty of dirty rats and squeaking mice.
HVAC and other things like water heaters seem to attract rodents. I don't want that gear in the attic in my house. I want it where I can see it frequently for easy inspection and make sure pests are not making a home due to the convenience.
What adds up to a mess like that?
1.) no periodic inspection by HO
2.) source of water and warmth in the attic (from a/c drain condensation and heater/water heater)
3.) rodent-friendly spaces (no traps or predators)