[Bugsinrugs]

I have been using my tractor the last few days and after fueling up I checked the oil and coolant. Dam rat chewed up my coolant cap and top of the reservoir. I’m picking up a new reservoir tomorrow but how do I deter these bastages? It’s usually park the tractor in my shed. I hate using rat poison because I have Horned Owls on my property and don’t want to kill them too. Any ideas out there?