I too was worried about impaction and eco earth. If you put the crickets in a glass bowl they can't climb out of it. I didn't believe it but it works! At first I had a bowl with a high side then switched to a short sideded kidney shaped bowl from the pet store and they still can't get out if it. Sometimes a cricket will get loose when I dump them in and the frogs get a mouthful of substrate but they are pretty good at pulling most of it out of their mouth.