Welcome to the breeding grounds, gunk enthusiast; time to learn your craft.

In order to start the roachening, you will need find a cockroach somewhere. All stations come with a 'Radical' Cockroach, such as Radical Steve or Radical Buscemi. Keep them safe. There are 3 kinds of cockroaches:

• Regular cockroaches
• Mutated cockroaches
• The rare Cockroach Matriarchs

Cockroaches can't live under 0°C temperatures, they will however survive any explosion, such as nuclear blasts, temperatures up to and including infinity and any pressure condition, from the vacuum of space to the star-dwarfing pressures of a R-UST chamber.

When a regular cockroach is exposed to mutagen in any shape or form, it has a 10% chance per dose to rapidly transform into a mutated cockroach and a 0.5% chance to mutate into a Matriarch. Mutated Cockroaches will retaliate (at first) when dosed with mutagen, which can be of use for hostile individuals.

The best way to get your cockroach hive to transform is by making mutagen smoke, either via manual reacting or grenades. If you're lucky you'll get a matriarch and can go onto Mutated Cockroach breeding.

Simply drop some food on the cockroach breeding room. Roaches will consume from 0.2u to 0.6u of Nutriment available on the food and replace it with equal amounts of toxin, then lay an egg, preferring to lay them under trash such as dirty dishes, empty snack packets, etc.

Once the nutriment in the food is fully consumed the cockroaches will stop breeding from it. Cockroaches can consume the nutriment from their own eggs to lay more eggs, this is intended. They'll also lay eggs after “feeding” on trash, but only once. This can save your colony in an emergency but is strictly inferior to actual feeding. The easiest way to acquire tons of Nutriment-rich food is to react 40u Milk with 5u Enzyme for a Cheese Wheel which contains 20u Nutriment.

A good way to transport cockroaches (or any simplemob) in large quantities is to make a barrel with some metal sheets. Just click-drag the cockroaches into the barrel. Be aware that barrels are mostly unused except for this particular purpose, so players that see you dragging one can (and probably will) kick the barrel, loosing all cockroaches you might've had inside.

When entering the chambers make sure to be on HELP intent, since walking on HARM intent crushes the cockroaches on that tile.

Matriarchs need living prey to lay their eggs onto, these eggs have a 40% chance to be fertile and make more mutated roaches. Get some monkey or monkey man onto their chamber, but be careful to not get eaten yourself. If you use plastic flap chambers, you can disarm-grab-throw your “sacrifice” inside. You can alternatively breed regular cockroaches and mutagen-smoke them onto their mutated form, but most of your regular roaches will die to the mutagen.

An unholy creation made in the deep halls of maintenance, it is able to create cockroaches, both regular and mutated. If mixed with equal parts nutriment, it makes 3 regular sized cockroaches. If mixed with 10 parts mutagen, it makes a mutated cockroach, with a 1/5 chance to make a cockroach matriarch instead. See here for a recipe.

Aside from the general gunk roaches make and imply, our wriggly fellas can be processed to get Cockroach Chitin, a mostly useless chemical but fun in its own way.

Regular cockroaches gib on death unless they die to Insecticide, which can be found in NutriVends (30u bottles), pest control crate Bug Zapper spray bottles or made by mixing saltwater with toxin.

A regular cockroach produces 0.5u Nutriment and 2-6u of Cockroach Chitin, while their eggs contain 2u Nutriment, 1-4u Cockroach Chitin and 0.2u Toxin.

Mutated Cockroach meat (including matriarchs) contains 5u Nutriment and 16u Cockroach Chitin per slab, while their eggs contain 1-5u Radium and 5-15u Toxin, making it a good ghetto source for both.

Chitin can be processed into 2 specialized chemicals, as a catalyst for cheaper Lithotorcrazine and as a main ingredient in Greyshirt Vodka, the only chem that reduces RAD_TICK, the counter that actually does all the radiation symptoms (The antirad chems reduce RADIATION but you'll still suffer all the negative effects from RAD_TICK until it counts to zero), it also reduces RADIATION better than Hyronalin.

Despite their appearances, Insectoids are not evolved from roaches.