We only have garden snakes so not sure what you mean by larger snakes. It's 1/2" squares, so any snake larger than 1/2" wide can't get through there. They do make it 1/4" but that's "overkill" for most of us as the point of it is to keep ALL varments out, including fox, raccoons, opossums, dogs, bobcats, skunks, etc. some of whom dig.Is 1/2" recommended to keep larger snakes out also? It seems like an overkill otherwise.