Fungus Gnats.... and a question

[Cazador]

A "fungus gnat" is a tiny little fly. They're attracted to rotting vegetation/fruit.

[Thamnophis]

A "fungus gnat" is a tiny little fly. They're attracted to rotting vegetation/fruit.

Ohhh, I thought the problem was mould (Fungus).

Those tiny flies can easily be driven away. Keep your terrarium clean.

[Stefan-A]

And remember to keep the substrate dry.