YES! That is a good idea, freeze and/or microwave as appropriate anything you add and try not to get any unwanted introducitons. Although your tortoises may benefit from a humid hide/burrow, make sure the general set up is fairly dry...(don't keep them like box turtles). I was thinking about your query, maybe they are springtails? Look closely and find a bug site on the web, you should be able to narrow it down. I doubt if they are harming your tortoises, but maybe they are annoying if abundant enough. Getting rid of them is a big project, as they may have layed eggs in the cracks of wood, soil etc. Good luck, Vic