for fellow tortoise owners who are trying to rid their enclosures of substrate gnats; this is a rolly polly aka pill bug, (Armadillidium vulgare). Under rocks and wood piles they make excellent natural control of the gnats; and stay put in the enclosure.
Very similar and serving the same purpose as their cousin a sow bug ;
And here is a pill bug showing it's name ; and to think, they are related to shrimp and lobster…light lemon-butter and I'm standing in line for seconds!!!
I use both in my indoor enclosures along with spring tails. If they don't get eaten first, they don't bother the turtles and keep the enclosure neat and tidy.