I'm no expert, but I would assume it depends on what kind of wood it is. And if it is safe, just make sure it's not pesticide-treated.gsgfg
I think your best bet would be looking around in areas that aren't treated by fertilizers or pesticides, if you can't find any to buy. I've never bought large branches like that for my enclosure so I'm not entirely sure.do you guys know anywhere to buy oak pieces safe for millipede use?