Probably spring tails. Look those up and see if they match. If yes, they are harmless detrivores and won't harm your tortoise. They also come from the environment and colonize our warm damp enclosures. I just ignore them.
Springtails are tiny tiny. Maybe you are thinking of silver fish?I thought springtails were much larger than what I'm seeing, so I didn't even consider them being what I see. Will try to get a better pic to help confirm. I had a bucket of coco coir left next to the tank on the floor and also found them in there. Do they wander around very much because if so... I have a divorce ahead of me. Lol
Thanks alot Tom! Always happy to trust your advice.