Hi again DwarfHog
I found this https://www.hedgehogstreet.org/forums/topic/rats-4/ which has some other links about rats contained in it. Hope you might find something useful.
But if you really want to stop rats getting hog food, it might mean supervised feeding, i.e. only feeding the hogs when you are about to watch and frighten any rats away. In the past, I have found that rats are much more sensitive to movement and sound than most hogs are. So it’s often possible to scare them away without the hogs noticing.
Good luck.
