Unmasking Cockroach Growth: Eggs, Nymphs & Adults

Understanding Cockroach Biology for Better Pest Management with Ned’s

Fast Growing Infesters

Roaches go through a straightforward life cycle: egg, nymph, and adult. Knowing each part of the cycle can help you call our Experts ahead of these pests becoming a bigger problem!

Egg

Cockroach reproduction starts with an egg case known as an ootheca. These small, brown casings resemble tiny capsules and typically range from 6 to 9 millimeters in length, comparable to a grain of rice or a dried bean. While some cockroach species retain the case until the eggs are ready to hatch, others conceal it in dark, protected spots.

What Ned’s Pest Experts Have to Say: “Don’t step on or squash an egg case! Eggs are resistant and could still hatch. Instead, call us for proper pest removal.”

Nymph

After hatching, cockroaches enter the nymph stage—a period of rapid growth and transformation. These wingless juveniles start off pale or nearly white, darkening with every molt. They gradually increase in size from just 2–3 millimeters to as much as 12–15 millimeters, undergoing 5 to 13 molts over a span ranging from one month to two years, depending on the species and environment.

Adult

When cockroaches reach adulthood, their size and lifespan vary widely. A German cockroach might only be 13 mm long, while an American cockroach can grow to double that length—up to 50 mm. As adults, they usually develop wings, although flying isn’t always part of their behavior. Depending on the environment and species, they can live from several months to two years, producing new egg cases on a regular 3–6 week cycle.

Know the Life Cycle

The presence of cockroaches at any stage—especially immature nymphs or discarded skins—can signal a larger issue. These clues often mean there’s an active colony forming nearby. Early detection is key to preventing widespread infestation.

If you see signs of cockroaches, contact Ned’s Pest Control today to stop the cycle before it spreads.