I keep my crickets in an old 10 gallon tank with a metal mesh lid on top. No escapes there since they can't climb the glass. With the exo-tera tank if you aren't using the holes in the back for anything close the openings, there is a little slider that covers the holes. Then cover them with a strong tape, like packing tape to seal it up. I use the glass bowl trick too but occasionally the frogs get a little nuts and there are crickets being flung all over the place.