Are they opposite sex (like one male to three females)? If not (in other words, if you have two males) this is very stressful. Your setup sounds good...large enough, warm enough. Do you have a not so hot spot so they can thermoregulate? Do you use gages to see the temps in the hot/cold parts and the humidity ranges? How often do you clean the cage and with what? How often do you feed d3? do you have uv lights? what wattage is your CHE? what type of substrate do you use?