Hundreds of animals utilize a single burrow? At the same time?
Anyway - I wasn't thinking of things like different small critters. I was thinking of more PET type animals like bearded dragons and a snake in the same cage. Or two different snakes in the same cage.
That's why I said "The smaller stuff may not be a problem..."
But I've known snakes to kill frogs, lizards, and other snakes, in the same terrarium. I wouldn't recommend those being kept together.