Due to this reason, many people advise against using soil as a bottom. Most people use just paper towel, enough to soak up water and gather feces. If you put the mesh netting, it would just make it possible for them to breed easier without the males eating the eggs. So in short, to keep them from digging, take out the soil. Another thought, if you really dont want to remove the soil would be to lessen the crickit amount. Maybe say, put three crickets at a time. This way he can keep up with the amount your putting in and wont leave the extras to dig. I know you probably want to keep the soil but it is also a breeding ground for bacterias. I just built my new cage and had all these same questions and answers from many people so decided against the bottom soil. Anyway, hope this helps.