Dubia Colony Smell. Help!

I need help with my dubia. My colony is a little over a year old now, and it was doing splendid. Recently, I had some mass die-offs of adults, but I figured some of them were just reaching the end of their lives. It was probably around 10 a day dying. This started early December, and I completely cleaned and washed out the colony twice since then, replacing egg crates both times. I spot clean all dead bodies every 2 days or so. I've noticed quite a strong smell. In the beginning, it did smell, but only a faint "roach" smell. Now it's the same smell, just amplified. Granted, I have way way more roaches now than I ever did. I would estimate around a few thousand. Is my colony just getting too big for the tub? Any advice for keeping the smell down? I'd appreciate any and all comments.

It's possible they are overcrowding a bit. They shouldn't be smelly though. Is there any rotting food in there? Has the humidity gotten higher causing mold or maybe bacterial buildup? If so I'd try to dry the air a bit for a while and see if that helps.