We were staying at Waratah Bay last year having a few days out of the tent and into a cabin to clean up a bit. My wife said she could hear something during the night, i said its just possums. In the morning i noticed the pikelet bag stewn on the floor and no other signes of the pikelets, i then noticed a hole in the fly wire screen where the rats had eaten their way in and devoured my missus breakfast haha she was pretty peeved off with em. They also ate her chewys and some tea bags were cracked open.
I have the plastic rat trap here at home that i got from safeway, rats and mice love peanut butter so a bit on the trap and wait for the crack, probably the quickest and humane way of dealing with them.