Hello. We are new to this. We are going to add some larger branches into our rats cage. The branches are rat safe (mulberry) and will be boiled and properly cooked. I don't want them to slip around and possibly hurt the rats. What can I use to secure them? I have seen some people use like a twine or string but that doesn't seem like it would last long. Is there a metal wire I can use or maybe just large zip-ties? Thank you.