Biter Capture and Biolab Production Guide

If you want biolabs online or you need a steady way to feed end-game science, you eventually have to deal with biter eggs and captive spawners. The catch is that this chain is easy to stall: you need the right research, the right capture setup, and constant bioflux fuel to keep eggs flowing. This guide walks you through unlocking it, capturing your first spawner, keeping it productive, and turning those eggs into biolabs and promethium science.

Unlock the chain in the right order

Do not treat this as one jump from midgame into end-game biology. Start by getting Captivity online first, because that is what opens the path to Biter egg handling. Captivity needs Agricultural science pack, military 3, and Rocketry, so you should aim for it only once your war and space progression are already moving.

From there, research Biter egg handling. That is the hinge point for the whole subsystem, because it unlocks the egg line and also sits in the prereqs for later steps. If your goal is Biolab, you will still need Production science pack, Utility science pack, and Uranium processing on top of Biter egg handling. If your goal is a self-contained captive-spawner setup, push further to Captive biter spawner, which also requires Cryogenic science pack and Kovarex enrichment process. If your goal is end-game research throughput, Promethium science pack needs Biter egg handling and Fusion reactor, and Research productivity sits behind Promethium science pack.

Here is the quick reference for the core recipes you will be using:

Capture your first wild spawner safely

Your first Captive biter spawner must come from the wild on Nauvis. Fire a Capture bot rocket at a biter spawner, and it will slowly convert the target over 20 seconds. Do not rush this step. The capture bot can be attacked and destroyed by nearby biters before the conversion finishes, and the spawner keeps producing biters the whole time.

Treat the capture like a combat job, not a building placement. Clear the area first, make sure the capture lane is defended, and keep pressure off the bot until the conversion completes. If you lose the bot, you lose the attempt and you still have the hostile spawner to deal with.

Once you reach Aquilo and research Captive biter spawner, you can craft them directly and place them by hand. Until then, your only path is the capture shot, so make the first one count.

Keep the captive spawner fed and stop the production stall

A Captive biter spawner does not take a recipe. It only needs a constant supply of bioflux as fuel, and that fuel is the bottleneck you should solve first. It consumes food at 100 kW, which means one bioflux lasts exactly one minute regardless of freshness. While fed, it regenerates health at 1 per second; while starving, it loses health at 1 per second and stops producing biter eggs.

Do not build the capture site before you have bioflux logistics in place. If the spawner starves, egg output shuts off and the spawner slowly degrades until it reverts into a normal biter spawner with full health. At that point, you have to capture it again.

The spawner produces 5 eggs every 10 seconds, or 0.5 eggs per second, and can hold up to 100 biter eggs. That means you need to plan for continuous removal, not just continuous feeding. If the output slot fills up, production time keeps ticking, but no additional eggs are created while it remains full. In other words: fuel alone is not enough; you also need a reliable collection path.

Use biter eggs without losing them to spoilage

Biter eggs are only produced by Captive biter spawner, and they spoil after 30 minutes. Do not let them sit in storage unless you already have a destination for them. If they spoil, they spawn a big biter that behaves like a normal biter, which turns your saved material into a combat problem.

The safest pattern is to move eggs straight from the spawner into use. If you want nutrients, send them to a Biochamber for Nutrients from biter egg; one Biter egg becomes 20 Nutrients in 2 seconds. If you want the eggs for infrastructure or science, route them directly into the next recipe instead of stockpiling them. Eggs inside a Captive biter spawner do not spoil while stored there, so the spawner itself is your safest buffer.

Also remember that Biter eggs are one of the two ways of farming nutrients on Nauvis, so you can use them to keep bio-production running as well as to feed higher-tier recipes.

Turn the egg line into biolabs and promethium science

Once the egg loop is stable, decide where those eggs should go. If your goal is research infrastructure, build Biolab first. A Biolab is crafted from a Lab, Biter egg, Refined concrete, Capture bot rocket, and Uranium-235. It is twice as fast as a standard lab and consumes science at half the rate, so it effectively gives double the research progress for the same pack consumption rate as a regular lab. The Lab research speed bonus still multiplies with the Biolab speed bonus, so your lab upgrades remain valuable.

If your goal is end-game science, reserve a separate egg stream for Promethium science pack. It is made in a Cryogenic plant from Promethium asteroid chunk, Quantum processor, and Biter egg. The pack is used for Research productivity, which is an infinite research and therefore worth pushing if you want every other technology to get easier over time. Since this pack only exists for that path, do not casually divert its ingredients into other lines.

The practical choice is simple: use one egg stream to expand your lab backbone, and another to feed Promethium science pack once you can support it. That keeps you from starving both goals at once.

Scale carefully and watch the edge cases

Do not overfocus on quality. Higher quality Captive biter spawner does not produce higher quality biter eggs, so quality chasing does not improve output. What quality does change is risk: if a captured spawner reverts into a normal spawner, it keeps its quality, and that quality can spread through the resulting biters and their expansion groups.

That means your real scaling priority is containment. Keep spare fuel ready, keep output moving, and do not leave Captive biter spawner sitting in inventory or another container, because it has a 30 minute spoil time there and then turns into a behemoth biter. If a spawner has already been captured and then starves, automated weapon systems generally will not target it, with the exception of rocket turrets and spidertrons loaded with Capture bot rocket. So if something goes wrong, you need an explicit cleanup plan instead of assuming defenses will solve it for you.

Build the chain like a logistics problem, not a trophy room: feed it, empty it, process it, and only then expand it. That is what keeps the entire biter-to-biolab pipeline from collapsing into an enemy wave.