Cork bark makes ideal natural hides in the vivarium. The bark is stripped from cork oak trees without any actual damage to the tree itself. This natural resource is taken without any disturbance to flora and fauna where it is collected and is a completely renewable natural resource.
 
There are many benefical factors of using cork bark including;
lightweight
doesn't rot
non-toxic
soft 
buoyant
 
Flat pieces of bark can be used in many situations such as. Proped up against a vivarium wall for lizards; amphibians. A natural snake hide; simply by laying it on the floor allowing the snake to burrow underneath. Place it in an aquarium style setup for newts allowing it to float on the surface so they can get in and out of the water.