Recipe for water crystals

[Mr. Mordax]

At the risk of people realising how thick I am - All I can see here is a Molotov Cocktail..! Do you fill the bottle with water and then place the bottle in with the colony? If so, won't many of the roach species be unable to climb to the wet wick?

It doesn't have to be glass. The zoo I've seen it in uses a largish delicup with a few holes poked in the lid to allow for several wicks. If it's low enough, you can make climbs leading up to it (with egg cartons, etc.) so the non-climbing roaches can reach it.

But, yeah, it may look a bit like a molotov cocktail when you're finished.