For me, rats are filthy, gross, and creepy. But that is not why I fight them. I normally would not care about their presence as long as they stay on their side of the walls. But I fight them for two reasons:

• Their teeth never stop growing. So they are teething their whole life and also build nests, which means non-stop house destruction.
• They can carry hantavirus. It’s an airborne transmission and can come from rat urine and feces.
• The day I decide to remove my ceilings (likely to take away rat turf), I expect to get a shower of feces.