Woodpeckers normally excavate a new gap every year, leaving the outdated gap for other cavity-nesting birds. Cactus spines discourage animals from climbing the cactus. Apparently, having said that, they don’t deter snakes. I’ve observed pictures of a gopher snake climbing a saguaro to prey to the dwellers in a hole. https://paulk259fox3.tnpwiki.com/user