It's roach droppings, old egg sacks, old molts, dead roaches, but apparently it's good, it becomes it's own substrate and maintains moisture, apparently...

As T-rad said.

But don't throw it out. As you will end up throwing roaches away. :eyepoke:

Get your self another container and throw the stuff into that container.
and then add a egg tray to that mix and and every now and then just remove egg tray and shack into larger colony.

Not good to re-use egg trays as it absorbs all the pee and the smell, it makes your colony stick a lot faster.
It is also much healthier with clean egg tray than re-used trays.

Best would be to use new egg cartons every time.

I used to replace eggflats every 6 months when my colony reached a boiling point where I needed to split the colony.

But you have to have a third container somewhere as some of the eggflats will have eggcases attached to them.

But now days I don't have time for COLOSSAL colonies as there is this person who keeps buying my colonies every time they reach a good 1000+

TIP:
The cleanliness of your colony depends on a few factors
a) container size - bigger is better
b) food / treats "food as in dry-mix" and treats as in "fruits and veggies"
c) water source "to avoid mold or attracting mite/lice or fruit flies" - provide a nice big bowl filled with "washed pool filter sand"

Dubai's, Hissers and Turks are one of the easiest roaches to keep and they are clean. The bigger the colony the more gas they produce. Yeah imagine 1000 people farting together to the tune of the nut cracker. So yes foul smelling gas in normal in Big colonies that is why ventilation is key, as they can gas themselves to death.

Blaberus fusca roches - don't get me started.

I was having the same problem when I moved my roach colony into a bigger tub... lots of babies left in the "substrate" (Poo, left over/dryfood/skin) but I just moved the trays into bigger tub and left an egg tray over the old junk and every time I go feed or grab some roaches just shake off that egg tray into ur new tub....
but you could always collect all the egg cases, not individually but all that gunk and put it in small tubs. Put single egg cups over so that any babies that hatch will climb onto the egg cup and then u can move them into a clean little tub and you have sling food ready to go? Ill take some pictures later of the process cause im still busy hahaha but yeah hopefully you understand the idea.... Echodive showed me the way, roach meister!

I'm glad I don't stay close to any on you guys that remove baby roaches and oothecae and throw them away... ever so often some one has a fit because of the restrictions on the pets trade by Natcon or what ever the impact might be if a exotic pet might escape... and some of you just put exotic roaches out with the trash!!! I used a few of the more "French and Dutch" words in my vocabulary while reading this!!! :igiveup:

I know it will seem extreme to most of you that has never moved into a house that has a roach(local) infestation... but I have roach traps standing around my colonies enclosures for the odd escapee and even go as far as to nuke oothecae that have not hatched in over due time hatched before I dispose of them. Roaches can survive Nuclear radiation and I have also by accident frozen some roaches and they survived that.

@FriedPet - I suggest you clean your colony enclosure more often and to make things easier for you get a separate enclosure into which you move the oothecae when you clean the enclosures, where they can hatch. This will make "managing" your colony easier. And cleaning it more often will make keeping it clean easier as well.

I use one of these small rechargeable vacs to suck up all the crap and use a solution of 25ml bleach dissolved in 500ml of water in a spray bottle to wipe down and clean my enclosures. I have also enquired about using F10 from the manufacturers, search my previous threads on the topic, but have not used it myself.

I found these trays... They are GREAT and made of plastic and you can re-use them after rinsing them with water as often as you like. I will try and find out what they are generally used for and where you can find them.