Hi Craic
First of all, do you feed the birds, because that is more likely to attract any rats, initially, than the hog food is.
Some rats aren’t at all interested in cat food – especially wet cat food. Some will take kitten/cat biscuits, but I’m not sure whether they actually eat them or cache them. But one rat I had here went within about a foot of a bowl of kitten biscuits and then backed away. So if you don’t have a problem with cats, I would try cat/dog food.
Sadly, it’s possible the rats might take over a hog box.
More information from previous posts about rats: https://www.hedgehogstreet.org/forums/topic/rat-probelm/
