I've had 3 male and 8 female dubia roaches along with about 20 nymphs for about a month or so and they are not breeding. They receive fresh organic fruits and veggies everyday along with water crystals. They also have a heat pad under the tank. Should I add an organic soil to the bottom of the container to help with humidity? Humidity is the only thing I can think of that could be wrong. Any tips, ideas? Thank you