(A mouse can jump nearly as high!)
I think it's wonderful that you have maintained a rat-free property, and I'm sure you'll continue to do so, safely...nicely done!
Um, the average Norway rat can jump 6 feet. Sorry...but this is a great thread, I'm reading intently...
We support a feral cat colony and haven't had a rat near any of our animals in 21 years...and like most of you we seal all animal food in covered containers.