Is that a matamata they're sitting on?
...until they murder you in your sleep with their insidious little blowguns!So freakin cute!!!
I kept my dart frogs for 12 years in an large enclosure with a plain soil floor. No fancy bio substrate.
This is where the confusion comes in, if they were on it, it would be bio. Almost any soil turns bio overtime. If it didn't you'd just see mold everywhere or something else unsightly. Or it would smell very badly. Technically when you buy a plant, the soil it comes in is bioactive.
Interesting. I guess I’ve always thought of plain soil as being inert.