If you are talking great big rats then you could use a metal barrel with a wire lid attached and holes drilled in it for air but not large enough for the rats. Mice now I don't know about holes. Sounds like it is time to call in the Calvary. Does a large Meow or 2 sound like the right bugle call? Ranchmama Okie zone 7a ******************* ----- Original Message ----- From: "Stacey Marien" <samarien@yahoo.com> > Washington DC - in a semi-detached row house. I have > a very small backyard and have had a pyramid composter > for a year now. The problem? Rats. > > Any advice for rat proofing my composter in the > backyard?