I use nylon or fiberglass screen ALL the time. Every lid I use has it. I don't like the metal screen because it rusts and is sharp as hell. Crickets can holes in it but if your using that many crickets you might be more worried about the crickets trying to chew on the gecko. Also, when crickets do chew holes they chew holes just big enough for their body to squeeze through. You should notice this long before the gecko has a chance to get out.