Living Wood Wall

The same wall exists in a safe and an unsafe form. The one already sitting inside a living tree shuts almost everything out and lets only a short list of critters through, which is why the inside of a natural living tree is so quiet. Anything you place yourself behaves like a normal wall and blocks spawns outright.

A living tree will not give you the wall when you break it. The mahogany trees in the underground jungle will, so if you want the natural article without touching a crafting station, that is the trip to make.

Dropping the crafted wall into shimmer returns the overgrown version, which looks identical but places the unsafe form. That is the only way to build with a wall that narrows spawns down to that critter list, which is genuinely useful if you want gnomes or bunnies turning up inside a themed build instead of nothing at all.