I had that problem for a while. I adjusted two issues and the problem really stopped.
1) It shouldn't be wet in there, but mild moisture and a constant source of water. Those cricket cubes dry up really quickly. I like water crystals better as they last longer. Mist the container every day, just a couple sprays.
2) They like it warm, but not too warm. The best way of figuring out what they want is to put the heating pad only under a quarter of the tank. If it is too hot they will be found on the far side, If not, they will be mostly over the pad. Adjust accordingly. I don't like to keep them too warm, because I like to keep the breeding a little slower.
I am overrun right now, so if anyone is interested , just write or call.
Talk to you later,
Matthew Wheelock, DVM
Dilworth Animal Hospital, Charlotte NC (704) 808-7387